clear
//
//given
//when currents are in same direction the total induction is:
//lt=l1+l2+2m
//when currents are in opposite direction the total emf is:
//lt=l1+l2-2m
//According to this problem
//l1+l2+2m=1.2
//l1+l2-2m=0.2
//Solving the above equations we get l1=0.4H M=0.25H
//on substituting we get l2=0.3H
//k=m/squareroot(l1*l2)
printf("\n k=0.72168")