If π is taken as 22/7, calculate the distance (in metres) covered by a wheel of diameter 35 cm, in one revolution.

A ladder 15 m long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then calculate the height of the wall.

A box contains cards numbered 6 to 50. A card is drawn at random from the box. Calculate the probability that the drawn card has a number which is a perfect square.

Solve the following for

Find the number of all three-digit natural numbers which are divisible by 9.