Question

# The average marks of $$48$$ students in a class is $$45$$. The average marks of the boys in the class is $$40$$ and the average marks of the girls in the class is $$50$$. What is the ratio between the numbers of boys and the number of girls in the class?

A
2;1
B
11:1
C
1:1
D
1:2

Solution

## The correct option is A $$1:1$$Total marks of $$48$$ students $$= 48 x 45 = 2160$$Let the number of boys be $$B$$ and the number of girls be $$(48 - B)$$Then total marks of boys $$= 40B$$Total marks of girls $$= 50 (48 - B) = 2400 - 50B$$$$\displaystyle \Rightarrow$$ $$40B + 2400 - 50B = 2160$$ $$\displaystyle \Rightarrow$$ $$10B = 240$$$$\displaystyle \Rightarrow$$ $$B = 24$$Thus number of girls $$= 48 - 24 = 24$$Therefore, required ratio $$= 24 : 24 = 1 : 1$$Mathematics

Suggest Corrections

0

Similar questions
View More

People also searched for
View More