A man arranges to pay off a debt of Rs 3600 by 40 annual installments which are in A.P. When 30 of the installments are paid he dies leaving one-third of the debt unpaid.
The value of the 8th installment is: Answers.
A) 50	B) 54	C) 65	D) 47	E) 37
Let the first installment be 'a' and the common difference between any two consecutive installments be 'd'   Using the formula for the sum of an A.P :-   S=n/2[2a+(n−1)d].   We have,   3600=40/2[2a+(40-1)d].   3600=20[2a+39d].   180 =2a+39d. ----(i)   Similarly,   2400=30/2[2a+(30-1)d].   160=2a+29d. ----(ii)   On solving both the equations we get:   d=2 and a=51   Hence, the Value of 8th installment is :-   =51+(8−1)2.   =65. Answer : 65
<result>C</result>
A man arranges to pay off a debt of Rs 3600 by 40 annual installments which are in A.P. When 30 of the installments are paid he dies leaving one-third of the debt unpaid.
The value of the 8th installment is: