What sum of money will amount to ₹ 27783 in one and a half years at 10% per annum compounded half-yearly ?

Ashok invests a certain sum of money at 20% per annum, compounded yearly. Geeta invests an equal amount of money at the same rate of interest per annum compounded half-yearly. If Geeta gets ₹ 33 more than Ashok in 18 months, calculate the money invested.

In what time will ₹ 1500 yield ₹ 496.50 as compound interest at 20% per year compounded half-yearly ?

Calculate the C.I. on ₹ 3500 at 6% per annum for 3 years, the interest being compounded half-yearly.