the number of boys and girls in a class are in the ratio 7:5. The number of boys is 8 more than the number of girls. What is the total class strength.
Answers
given:
let the no. of girls be 5x and boys be 7x
the no. of of boys is 8 more than the no. of girls
so no. of boys = no. of girls + 8
> 7x = 5x +8
> 7x - 5x = 8
> 2x = 8
> x = 8/2
> x = 4
no. of boys = 7x = 7 ×4
= 28
no. of girls =5x = 5×4
= 20
so no. of boys is 28 and no. of girls is 20
Answer:
Step-by-step explanation:
Let,
Given,
number of boys in class = 7x
number of girls in class = 5x
So,
The total strength of class should be 7x + 5x -- equation (i)
Again
The number of boys is 8 more than the number of girls or 7x = 5x + 8 -- equation (ii)
Then
Solving equation (i) & (ii)
⇒ 7x + 5x = 7x + 5x
⇒ 7x + 5x = (5x +8) + 5x -- [putting the value of 7x from equation (ii) ]
⇒ 7x + 5x = 5x + 8 + 5x
⇒ 12x = 10x + 8
⇒ 12x - 10x = 8
⇒ 2x = 8
⇒ x = 8/2
⇒ x = 4
And now solving equation (i) to get total strength of class.
⇒ Total strength of class = 7x + 5x
⇒ Total strength of class = 7(4) + 5(4)
⇒ Total strength of class = 28 + 20
⇒ Total strength of class = 48
Hence, the total class strength is 48.