28. If the amount of Rs. 360 in 3 years is Rs. 511.20, what will be the amount of Rs. 700 in 5 years?

29. Simple interest on a certain sum at a certain rate is of the sum. It the number representing rate per cent and time in years be equal, then the time is:

30. A man lends Rs. 10000 in four parts. If be gets 8% on Rs. 2000 7 on Rs. 4000 and 8 on Rs. 1400 what per cent must he get for the remainder, if the average interest is 8.13%?