The average weight of all the students in a class is 55 kg. The ratio of the average weight of boys to that of girls is 5:4. If `40%` of the students are boys and the rest are girls, then what is the average weight (in kg) of boys?

The average weight of 45 students in a class is 52 kg. 5 of them whose average weight is 48 kg leave the class and other 5 students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class?

The mean weight of 150 students in a class is 60 kg. the mean weight of boys is 70 kg and that of girls is 55 kg. What is the number of boys in the class?

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 ?

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 mean weight of 100 students in a class is 46 kg. The mean weight of boys is 50 kg and that of girls is 40 kg. The number of boys exceeds the number of girls by

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 score of 84 students (boys and girls) in a test is 57 . The ratio of the number of boys to that of girls is 10 : 11 . The average score of boys is 20% less than that of girls. What is the average score of girls in the test?

The average weight of girls is 15 and the average weight of boys is 30 and the average weight of boys and girls both is 25. If the number of boys are 12, then the number of girls is :