John borrowed Rs 20,000 for 4 years under the following conditions :
10% simple interest for the first `2(1)/(2)` years.
10% C.I. for the remaining one and a half years on the amount due after `2(1)/(2)` years, the interest being compounded half-yearly.
Find the total amount to be paid at the end of fourth year.

Answer

Rs 28,940-63