A sum of rs 20000 is invested for 15 months at 10% p.a compounded half yearly. What is the percentage gain, correct to one decimal place for 15 months

Let us first calculate the amount after 12 months. After 6 months, the amount becomes 20000*1.05 = 21000 After 12 months, the amount becomes 21000*1.05 = 22050 Three months later, the amount becomes 22050*1.05^(1/2) = 22594. So, gain is 2594/20000 = 13%