A man covers a journey from meerut to delhi by a car at an average speed of 40 Km/hr. He returns back by scooter with an average speed 24 km/hr. Find his average speeed during the whole journey?

The average weight of 40 students in a class is 30 Kgs. While the average weight of 20 students of another class is 35 Kgs.Find the average weight of the both class?

The average weight of 12 students in a class is increased by 2 Kg. When a student who weights 45Kg. is replaced by a new student. Find the weight of new student?

new weight = Old weight+no of items x decreased or increased in average

=45+12x2=69

8.

In a boat 25 persons were siting. their average weight increased one kilogram when one man goes and a new man comes in. The weight of the new man is 70 Kgs. Find the weight of the man who is going.