There are 50 students in a class, of which 40 are boys. The average weight of the class is 44 kg and that of girls is 40 kg. find the average weight of the boys.

20 % of 25 students in a class are boys.How many girls are in the class?

the weight of 72 books is 9 kg.What is the weight of 40 such books?

A class consists of 50 students out of which 30 are girls, the mean of mark scored by girls in a test is 45 and that of boys is 30. determine the mean score of the whole class.

There are 25 students in a class in which 15 boys and 10 girls. The class teacher select either a boy or girl for monitor of the class. In how many ways the class teacher can make this selection?

there are 376 bags of rice in a godown .If each bag weighs 98 kg 725 gm,find the total weight ofthese bags.

There are 40 scholars in a class, out of which 10 are sports- persons. Three scholars are selected at random out of them. Find the probability distribution for the selected persons who are sports-persons. Find the mean of the distribution.

The distribution below gives the weights of 30 students of a class. Find the median weight of the students.

Consider the frequency distribution table (Table 14.3, Example 4, Chapter 14), which gives the weights of 38 students of a class. (i) Find the probability that the weight of a student in the class lies in the interval 46-50 kg. (ii) Give two events in this context, one having probability 0 and the other having probability 1.