Question

In a school, `4/5` of the children are boys. If the number of girls is 200, find the number of boys.

Answer 1

No. of boys = `4/5` of the total children

∴ No. of. girls = `(1 - 4/5)` of total children

`= (5 - 4)/5 = 1/5` of total children

But no. of girls = 200

∴ `1/5` of total children = 200

Hence total number of children = `200 xx 5/1 = 1000`

∴ No. of boys = `4/5` of 1000 = `4/5 xx 1000 = 800`

Answer 2

To find the number of boys, let the total number of children be x.

`1/5` of the total children = 200.

`1/5 x = 200`

Multiply both sides by 5:

x = 200 × 5 = 1000

So, the total number of children is 1000.

The number of boys is `4/5`​ of the total number of children:

Number of boys `= 4/5 xx 1000`

= 800