If 4 men and 6 boys can do a work in 8 days and 6 men and 4 boys can do the same work in 7 days, then how many days will 5 men and 4 boys take to do the same work?

The difference between Simple Interest & Compound Interest for the fourth year is Rs 7280 at 20% per annum. What is the principal amount.

Places A and B are 396 km apart. Train X leaves from A for B and train Y leaves from B for A at the same time on the same day on parallel tracks. Both trains meet after \(5\frac{1}{2}\) hours. The speed of train Y is 10 km/h more than that of train X. What is the speed (in km/h) of train Y?

If cosecθ - cotθ = \({1 \over a}\), then \( {a^2-1 \over a^2+1}\) is