Two circles touch each other externally. The distance between their centres is 7 cm. If the radius of one circle is 4 cm, then the radius of the other circle will be
A girl walking at the speed of 2 km/hr covers a certain distance in 7 hours 30 minutes. If she covers the same distance by cycle in 5 hours, then what is the speed (in km/hr) of cycle?
The length and breadth of a rectangular piece of a land are in a ratio 5:3. The owner spent Rs. 6000 for surrounding it from all sides at Rs.7.50 per metre. The difference between its length and breadth is