Renu takes `2 1/5` minutes to walk around the school ground. Snigdha takes `7/4` minutes to do the same. Who takes less time and by what fraction ?

Solve the following: Rani takes 30 minutes to reach school from home. Ismail take 1/2 an hour to cover the same distance. Find the ratio of time taken by Rani to the time taken by Ismail.

An electric bettle has two coils. When one coil is switched on it takes 15 minutes and the other takes 30 minutes to boil certain mass of water. The ratio of times taken by them, when connected in series and in parallel to boil the same mass of water is :

Two closed containers of same dimensions made of different materials are completely filled with ice. The ice in the first container takes 20 minutes and that in the second container takes 10 minutes, respectively for complete melting. The ratio of the thermal conductivities of the materials of the two containers is _______

A man travels 370 km partly by train and partly by car. If he covers 250 km by train and the rest by car, it takes him 4 hours. But if he travels 130 km by train and the rest by car, it takes 18 minutes more. Find the speed of the train and that of the car.

A train takes 45 minutes to travel 51 kms. If the same train travels 221 kms, how much time is taken by it?