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 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.

In a class, the average marks of boys is 520 and that of the girls is 420. If the average marks per student is 500, the percentage of boys in the class is …….

The average age of all the students of a class is 22 years. The average age of boys of the class is 24 years and that of the girls is 20 years. If the number of girls in the clss is 30, then the find the number of studnets in the class.

The average age of all the students of a class is 18 years. The average age of boys of the class is 20 years and that of the girls is 15 years. If the number of girls in the class is 20, then find the number of boys in the class. (a) 15 (b) 30 (c) 45 (d) 50