Question

John deposited 400 every month in a bank's recurring deposit account for 2.5 years.
If he gets 1085 as interest at the time of maturity, then the rate of interest per annum​

Answer 1

Answer:

formula is interest = ((P*n*(n+1))/(2*12))*(r/100)

=> 1085 = (400*30*31*r /(2*12*100))

=> 1085 = 155r

=> r = 7 percent per annum