Find the angle of elevation of the sun at that moment?

The ratio of the length of a vertical rod and the length of its shadow is .

If the mean of the first n natural number is 15, then find n.

Two cones have their heights in the ratio 1 : 3 and radii in the ratio 3 : 1. What is the ratio of their volumes?

A die is thrown once. What is the probability of getting an even prime number?

In Fig. 2 DE || AC and DC || AP. Prove that

OR

In Fig, 3, two tangents TP and TQ are drawn to a circle with centre O from an external point T. Prove that ∠PTQ = 2 ∠OPQ.