clc
//initialisation of variables
w=3000//sq ft
w1=2000//sq ft
w2=1000//sq ft
r=15//in
a=12//in
h=7.5//in
//CALCULATIONS
G=w*(r/a)*h//gal
g=w1*(r/a)*h//gal
g1=w2*(r/a)*h//gal
//RESULTS
printf('the normally be stored to tide the supply over dry spells=% f gal',G)