Question

The number of students in a class is 60. The number of boys is seven-fifths the number of girls. Find the number of boys in the class.

Answer 1

Explanation:

Let the number of girls = x

Therefore, no. of boys =
`(7)/(5) * x`

`\because \: no \: of \: boys + no \: of \: girls \: = 60 \\ \\ \therefore \: (7)/(5) x + x = 60 \\ \\ \therefore \: (7x + 5x)/(5) = 60 \\ \\ \therefore \: (12x)/(5) = 60 \\ \\ \therefore \: x = 60 * (5)/(12) \\ \\ \therefore \: x = 5 * 5 \\ \\ \therefore \: x = 25 \\ \\ \therefore \: (7)/(5) x = (7)/(5) * 25 = 7 * 5 = 35 \\`

Thus, no of boys in the class is 35.