A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of 30∘ , which is approaching the foot of the tower with a uniform speed. Six seconds later, the angle of depression of the car is found to be 60∘ . Find the time taken by the car to reach the foot of the tower from this point.

How do you find the Maclaurin series for tanx?

Why is Axiom 5, in the list of Euclid’s axioms, considered a ‘universal truth’? (Note that the equation is not about the fifth postulate.)

The smallest composite number is ______.

(a) 2

(b) 4

(c) 1

(d) None of these

Find the arithmetic mean of the first ten odd natural numbers.

A boat goes 24 km upstream and 28 km downstream in 6 hours. It goes 30 km upstream and 21 km downstream in 6 hours and 30 minutes. The speed of the boat in still water is

A. 10 km/hr

B. 4 km/hr

C. 14 km/hr

D. 6 km/hr