Given details are,
Principal (p) = Rs 15625
Rate (r) = 16% per annum = 16/4 = 4% (quarterly)
Time (t) = 9 months = 9/12 ×4 = 3quarters of a year
By using the formula,
A = P (1 + R/100) n
= 15625 (1 + 4/100)3
= 15625 (104/100)3
= Rs 17576
∴ CI = Rs 17576 – 15625 = Rs 1951