If the numerator of a fraction is increased by 140%, and the denominator is increased by 150%, the resultant fraction is $4 \over 15$ . What is the original fraction?

On atest consisting 150 questions carrying 1 mark each, Meenal answered 80% of the first 75 questions correctly. What per cent of the other 75 questions does she need to answer correctly to score 60% on the entire exam?

The difference between the amount of compound interest and simple interest accrued on an amount of Rs 26,000 at the end of 3 years is Rs 2994.134. What is the rate of interest p.c.p.a.?

On a shelf there are four books on Economics, three on Management and four on Statistics. In how many different ways can the books be arranged so that the books on Economics are kept together?

6 women and 6 men together can complete a piece of work in 6 days. In how many days can 15 men alone complete the piece of work if 9 women alone can complete the work in 10 days?

From the first and the last sentence we get that work done by 36 women and 36 men in one day is equal to the work done by 90 women in one day, ie

36 W + 36 M = 90 W

36 M = 54 W

1 M = 1.5 W

Now, if 90 women can finish the whole work in a day, this implies that 60 men = 90 $\div$ 1.5 can finish the whole work in a day. Thus, if the work is entrusted to a group of 15 men then the required time to finish the work is 60 $\div$ 15 = 4 days.

Ravi borrowed some money at the rate of 4 p.c.p.a. for the first three years, at the rate of 8 p.c.p.a. for the next two years, and at the rate of 9 p.c.p.a. for the period beyond 5 years. If he pays a total simple interest of Rs 19,550 at the end of 7 years, how much money did he borrow?