Diameter of a car wheel is 21 cm. A car driver moving at the speed of 66 km/hr takes 36 seconds to reach a destination. How many revolutions will the wheel make during the journey?
Amit's age is four times the age of Babli. Babli's age is three times the age of Priya. If the present age of Priya is 5 years, what is the present age (in years) of Amit?