Question

Meena has cumulative deposit amount Rs.400 per month at 10% per annum simple interest. If she gets Rs.26550 at the time of maturity, find the total time for which the account was held.​

Answer 1

Answer:

If p is the deposit amount every month and r is the rate of interest, then interest I of cumulative deposit for n months is given by

(Refer the image for calculation)

above equation is simplified as n2 + 241n - 18060 = 0-----------(1)

after factorising LHS of eq. (1), it is rewritten as, (n+301)(n-60) = 0

hence n = 60 months = 5 years