{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 13: Profit and Loss"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.1, Page number 13.6"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "loss in 1st case is 29 Rs\n",
      "gain in 2nd case is 20 Rs\n",
      "loss in 3rd case is 25.0 %\n",
      "gain in 4th case is 25.0 %\n",
      "SP in 5th case is 99.0 Rs\n",
      "SP in 6th case is 15.0 Rs\n",
      "CP in 7th case is 70.0 Rs\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "C1=125;    #CP of 1st article(Rs)\n",
    "S1=96;     #SP of 1st article(Rs)\n",
    "C2=112;    #CP of 2nd article(Rs)\n",
    "S2=132;     #SP of 2nd article(Rs)\n",
    "C3=120;    #CP of 3rd article(Rs)\n",
    "S3=90;     #SP of 3rd article(Rs)\n",
    "C4=80;    #CP of 4th article(Rs)\n",
    "S4=100;     #SP of 4th article(Rs)\n",
    "C5=90;    #CP of 5th article(Rs)\n",
    "G5=10;    #gain(%)\n",
    "L6=25;    #loss(%)\n",
    "C6=20;    #CP of 6th article(Rs)\n",
    "S7=84;     #SP of 7th article(Rs)\n",
    "G7=20;    #gain(%)\n",
    "\n",
    "#Calculation\n",
    "x1=S1-C1;\n",
    "L1=-x1;       #loss in 1st case(Rs)\n",
    "x2=S2-C2;\n",
    "G2=x2;       #gain in 2nd case\n",
    "x3=S3-C3;\n",
    "L3=-x3*100/C3;    #loss in 3rd case(%)\n",
    "x4=S4-C4;\n",
    "G4=x4*100/C4;    #gain in 4th case(%)\n",
    "S5=(100+G5)*C5/100;    #SP in 5th case(Rs)\n",
    "S6=(100-L6)*C6/100;    #SP in 6th case(Rs)\n",
    "C7=S7/(1+(G7*0.01));    #CP in 7th case(Rs)  \n",
    "\n",
    "#Result\n",
    "print \"loss in 1st case is\",L1,\"Rs\"\n",
    "print \"gain in 2nd case is\",G2,\"Rs\"\n",
    "print \"loss in 3rd case is\",L3,\"%\"\n",
    "print \"gain in 4th case is\",G4,\"%\"\n",
    "print \"SP in 5th case is\",S5,\"Rs\"\n",
    "print \"SP in 6th case is\",S6,\"Rs\"\n",
    "print \"CP in 7th case is\",C7,\"Rs\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.2, Page number 13.7"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "SP of 2nd article is 750.0 Rs\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "S1=450;      #SP of 1st article(Rs)\n",
    "x1=25;     #loss(%)\n",
    "x2=25;     #gain(%)\n",
    "\n",
    "#Calculation\n",
    "S2=S1*(100+x2)/(100-x1);      #SP of 2nd article(Rs)\n",
    "\n",
    "#Result\n",
    "print \"SP of 2nd article is\",S2,\"Rs\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.3, Page number 13.7"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain in transaction is 25.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "n=25;     #number of articles on CP\n",
    "N=20;     #number of articles on SP\n",
    "\n",
    "#Calculation\n",
    "x=(n-N)*100/N;     #gain in transaction(%)\n",
    "\n",
    "#Result\n",
    "print \"gain in transaction is\",x,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.4, Page number 13.7"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "number of oranges per rupee is 32.0\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "S1=1/36;      #SP of 1st article(Rs)\n",
    "x1=4;     #loss(%)\n",
    "x2=8;     #gain(%)\n",
    "\n",
    "#Calculation\n",
    "S2=S1*(100+x2)/(100-x1);      #SP of 2nd article(Rs)\n",
    "n=1/S2;     #number of oranges per rupee\n",
    " \n",
    "#Result\n",
    "print \"number of oranges per rupee is\",n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.5, Page number 13.7"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "sale rate of rice is Rs 50.0 per kg\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "q1=2;      #quantity(kg)\n",
    "q2=10;     #quantity(kg)\n",
    "C=600;     #cost price(Rs)\n",
    "\n",
    "#Calculation\n",
    "S=C/(q1+q2);     #sale rate of rice(Rs)\n",
    "\n",
    "#Result\n",
    "print \"sale rate of rice is Rs\",S,\"per kg\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.6, Page number 13.8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 11.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "S1=455;      #SP of 1st article(Rs)\n",
    "S2=555;      #SP of 2nd article(Rs)\n",
    "x1=9;     #loss(%)\n",
    "\n",
    "#Calculation\n",
    "x2=(S2*(100-x1)/S1)-100;     #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",x2,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.7, Page number 13.8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "real profit is 25.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "p=20;      #profit on SP(%)\n",
    "\n",
    "#Calculation\n",
    "rp=p*100/(100-p);     #real profit(%)\n",
    "\n",
    "#Result\n",
    "print \"real profit is\",rp,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.8, Page number 13.8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "real loss is 9.09 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "l=-10;      #loss on SP(%)\n",
    "\n",
    "#Calculation\n",
    "rl=-l*100/(100-l);     #real loss(%)\n",
    "\n",
    "#Result\n",
    "print \"real loss is\",round(rl,2),\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.9, Page number 13.8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "percentage increase of MP is 40.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "d=10;    #discount(%)\n",
    "g=26;    #profit(%)\n",
    "C=1;   #assume\n",
    "\n",
    "#Calculation\n",
    "x=C*(100+g)/(100-d);     \n",
    "M=(x-1)*100;     #percentage increase of MP(%)\n",
    "\n",
    "#Result\n",
    "print \"percentage increase of MP is\",M,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.10, Page number 13.8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 8.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "S1=30;      #SP of 1st article(Rs)\n",
    "x1=20;     #gain(%)\n",
    "d=10/100;   #discount\n",
    "\n",
    "#Calculation\n",
    "S2=S1*(1-d);      #SP of 2nd article(Rs)\n",
    "x2=(S2*(100+x1)/S1)-100;     #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",x2,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.11, Page number 13.9"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "number of oranges per rupee is 14.0\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x=40;     #gain(%)\n",
    "S=1/10;   #SP of article(Rs)\n",
    "\n",
    "#Calculation\n",
    "y=(x/100)+1;\n",
    "C=S/y;      #CP of article(Rs)\n",
    "n=1/C;     #number of oranges per rupee\n",
    "\n",
    "#Result\n",
    "print \"number of oranges per rupee is\",n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.12, Page number 13.9"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 50.0 %\n",
      "number of oranges is 312.0\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "SP=1/4;    #SP of article\n",
    "CP=1/6;    #CP of article\n",
    "tg=26;    #total gain(Rs)\n",
    "\n",
    "#Calculation\n",
    "g=(SP-CP)*100/CP;      #gain(%)\n",
    "x=tg/(SP-CP);        #number of oranges\n",
    "\n",
    "#Result\n",
    "print \"gain is\",g,\"%\"\n",
    "print \"number of oranges is\",x"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.13, Page number 13.9"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 11.11 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x=0;\n",
    "Tw=1000;      #true weight(kg)\n",
    "Fw=900;     #false weight(kg)\n",
    "\n",
    "#Calculation\n",
    "G=(Tw*(100+x)/Fw)-100;      #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",round(G,2),\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.14, Page number 13.9"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "false scale length is 78.26 cm\n",
      "answer varies due to rounding off errors\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "Ts=100;   #true scale(cm)\n",
    "G=15;    #gain(%)\n",
    "x=10;    #loss(%)\n",
    "\n",
    "#Calculation\n",
    "l=Ts*(100-x)/(100+G);     #false scale length(cm)\n",
    "\n",
    "#Result\n",
    "print \"false scale length is\",round(l,2),\"cm\"\n",
    "print \"answer varies due to rounding off errors\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.15, Page number 13.10"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 96.56 %\n",
      "answer given in the book is wrong\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x1=25;    #gain(%)\n",
    "x2=-20;    #loss(%)\n",
    "\n",
    "#Calculation\n",
    "x=2*(100+x1)*(100+x2);\n",
    "y=100+x1+100+x2;\n",
    "g=(x/y)-1;        #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",round(g,2),\"%\"\n",
    "print \"answer given in the book is wrong\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.16, Page number 13.10"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "overall loss is -1.44 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x=12;     #loss or gain(%)\n",
    "\n",
    "#Calculation\n",
    "l=-(x/10)**2;      #overall loss(%)\n",
    "\n",
    "#Result\n",
    "print \"overall loss is\",l,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.17, Page number 13.10"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "cost price of 1st watch is 224.0 Rs\n",
      "cost price of 2nd watch is 336.0 Rs\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "C1=10/100;     #loss\n",
    "C2=15/100;     #profit\n",
    "C=560;     #cost(Rs)\n",
    "\n",
    "#Calculation\n",
    "C1=C1*C/(C1+C2);     #cost price of 1st watch(Rs)\n",
    "C2=C-C1;      #cost price of 2nd watch(Rs)\n",
    "\n",
    "#Result\n",
    "print \"cost price of 1st watch is\",C1,\"Rs\"\n",
    "print \"cost price of 2nd watch is\",C2,\"Rs\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.18, Page number 13.11"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "cost price of book is 90.0 Rs\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "C1=100;     #CP of book(Rs)\n",
    "p1=20/100;     #profit\n",
    "C2=80;     #assume 20% less\n",
    "p2=25/100;   #profit in 2nd case\n",
    "d=18;     #given difference(Rs)\n",
    "\n",
    "#Calculation\n",
    "S1=C1*(1+p1);     #selling price of book(Rs)\n",
    "S2=C2*(1+p2);      #selling price in 2nd case(Rs)\n",
    "S=S1-S2;     #difference when CP=100(Rs)\n",
    "CP=d*C1/S;   #cost price of book(Rs)\n",
    "\n",
    "#Result\n",
    "print \"cost price of book is\",CP,\"Rs\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.19, Page number 13.11"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "cost price of the book is 420.0 Rs\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "d=16;     #discount(%)\n",
    "M_S=80;    #cost(Rs)\n",
    "\n",
    "#Calculation\n",
    "S=(100-d)*M_S/d;      #cost price of the book(Rs)\n",
    "\n",
    "#Result\n",
    "print \"cost price of the book is\",S,\"Rs\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.20, Page number 13.11"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain in transaction is 11.11 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "n=30;     #number of articles on CP\n",
    "N=27;     #number of articles on SP\n",
    "\n",
    "#Calculation\n",
    "x=(n-N)*100/N;     #gain in transaction(%)\n",
    "\n",
    "#Result\n",
    "print \"gain in transaction is\",round(x,2),\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.21, Page number 13.12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "selling price of salt is 88.0 paise per kg\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x=80;    #quantity(kg)\n",
    "y=20;    #quantity(kg)\n",
    "C=88;    #cost price(Rs)\n",
    "\n",
    "#Calculation\n",
    "S=C/(x+y);     #selling price of salt(Rs)\n",
    "\n",
    "#Result\n",
    "print \"selling price of salt is\",S*100,\"paise per kg\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.22, Page number 13.12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "profit on the article is 20.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "l=10;    #loss(%)\n",
    "f=3/4;   #fraction \n",
    "\n",
    "#Calculation\n",
    "SP=(100-l)/f;      #ratio of SP to CP(%)\n",
    "p=SP-100;     #profit on the article(%)\n",
    "\n",
    "#Result\n",
    "print \"profit on the article is\",p,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.23, Page number 13.12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 50.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "N=66;    #length of cloth(m)\n",
    "x=22;    #gain in length(m)\n",
    "\n",
    "#Calculation\n",
    "g=x*100/(N-x);     #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",g,\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.24, Page number 13.12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "gain is 33.33 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "N=66;    #length of cloth(m)\n",
    "Y=22;    #gain in length(m)\n",
    "\n",
    "#Calculation\n",
    "g=Y*100/N;     #gain(%)\n",
    "\n",
    "#Result\n",
    "print \"gain is\",round(g,2),\"%\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example number 13.25, Page number 13.12"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "loss is 25.0 %\n"
     ]
    }
   ],
   "source": [
    "#importing modules\n",
    "import math\n",
    "from __future__ import division\n",
    "\n",
    "#Variable declaration\n",
    "x=-22;     #loss in length(m)\n",
    "N=66;      #length of cloth(m)\n",
    "\n",
    "#Calculation\n",
    "l=-x*100/(N-x);     #loss(%)\n",
    "\n",
    "#Result\n",
    "print \"loss is\",l,\"%\""
   ]
  }
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