If A and B together can complete a piece of work in 20 days and B alone in 25 days, in how many days can A alone complete the work?

If \(sec \theta + \frac{1}{cos \theta}=2\), find the value of \(sec^{55} \theta + \frac{1}{sec ^{55} \theta}\).

Mohan takes 2 hours more than Kishore to walk 63 km. If Mohan increases his speed by 50%, then he can make it in 1 hour less than Kishore. How much time does Kishore take to walk 63 km?

If x & y are acute angle, x+y <90° & sin(2x - 20°) = cos(2y + 20°), the value of sec(x + y) is