Question

in the school there is a total of 640 children the ratio of the number of girls to the number of boys is 7:9 how many boys are there in the school

Answer 1

360 boys

Explanation:

Firstly, you would do 7+9 to the ratio to get 16

Then you would do 640 divided by 16 to get an answer of 40

After this you would do 7x40 and 9x40 on the ratio to get an answer of 280:360, it's asking for boys and therefore it would be 360 boys.

To check your answer you can do 280+360 on the ratio and it should equal 640 which means you have the right answer.