What will come in place of the question mark (?) in the following questions ?
For the following questions answer them individually
A and B together can finish a work in 9 days. A alone can finish the work in 12 days. In how many days will B alone finish the work ?
The ratio of the number of boys and girls in a school is 9 7. If the number of boys increases by 40%, and that of girls by 20% what will be the new ratio of the boys and girls respectively ?
In what time would the simple interest on a certain sum be 0.125 times the principal at 10% per annum ?
