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?
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?