For Okhi relief fund, the girls of `9 A` donated rupees 4400 , and the boys donated rụpees `4200 .` The average amount given by the girls is rupees 200 and that of boys is rupees 150 : Then,
a) How many students are there in the class?
b) Find the average amount given by the students of `9 A`.

40 children of class VI donated 50 rupees on average to the Mutual Aid Fund. 30 children of class V donated 800 rupees in all. If we consider both classes together, how much did each donate on average?

In a class of 100 students, there are 70 boys whose average marks in a subject are 75.If the average marks of the complete class is 72. then what is the average of the girls?

Shyam bought 5 two hundred page notebooks and 3 hundred page notebooks from the school store. The price. of a two hundred page book is 9 rupees and the price of a hundred page book is 4 rupees. How much did Shyam spent? Use any letters you like for the number of two hundred page note books bought from this store, the number of hundred page books bought and the total amount of money spent by a student, and write the relation connecting them.

From a class of 12 boys and 10 girls, 10 students are to be chosen for a competition, including at least 4 boys.and 4 girls. The two girls who won the prizes last year should be included. In how many ways can the selection be made?

There are 50 children ina class.Thirty of them are girls . There are 40 children in another class. 25 of them are boys.One student is taken from each class at random. What is the number of outcomes ? How many out comes contain both boys. How many outcomes contain both girls. How many out comes have one boy and one girl.

A class consists of 40 girls and 60 boys. In how many ways can a president, vice president, treasurer and secretary be chosen if the treasurer must be girl, the secretary must be a boy and a student may not hold more than one office.

Out of 9 outstanding students of a school,there are 4 boys and 5 girls.A team of 4 students is to be selected for a quiz competition.Find the probability that 2 boys and 2 girls are selected.

Riyas calculates the total length of uniform cloth required for the students of his class. Boys require 1.25 metres each and girls require 1.75 metres each. There are 20 boys and 23 girls in the class. Then how many metres of cloth are required in all?