Question

A man arranges to pay rs 90000 in 40 monthly installments which are in A.P. when 30 installments are paid , he dies leaving one third of the debt unpaid . Find the value of second installments

Answer 1

2a+39d=4500
2a+29d=4000
d=50
a=(4000-29*50)/2=1275
2nd installment=1275+50=1325