The average weight of 25 students of a class is 28 kg. If the average weight of all the boys is 30 kg and average weight of all the girls is 25 kg, then find the number of boys in the class.

The average marks of 50 students of a class is 76. If the average marks of all boys is 70 and that of all girls is 80 in that class, then find the number of boys in the class.

The average weight of 55 students is 55 kg , and the average weight of another 45 students is 45 kg . Find the average weight of all the students .

The average weight of a class of 15 boys and 10 girls is 38.4 kg . If the average weight of the boys is 40 kg, then what is the average weight of the girls ?

If the average weight of the students of a class is 15kg, the average weight of the students of another class is 30kg and average weight of the students of both the classes is 25kg, then find the ratio of the number of students of the first class to the another class.

There are 50 students in a class in which boys are 8 more than the girls. Average weight of all the students is 50.5 kg and the average weight of all the girls is 48.5 kg then find the average weight of all the boys.