If the amount received at the end of 2nd and 3rd year at compound Interest on a certain Principal is Rs 9,600 and Rs 10,272 respectively, what is the rate of interest (in %)?
The initial ratio of sugar to flour in a dough was 2 : 7. To 9 kg of the dough John added more sugar to make the sugar to flour ratio 2 : 5. How much sugar did John later add?