Question

Divide 72 in a ratio of 3:5

Answer 1

The ratio is 3:5.

`(x)/(y)=(3)/(5) \ \ \ |\hbox{cross multiply} \\ 5x=3y \ \ \ |/ 5 \\ x=(3)/(5)y`

You have to divide 72, so the sum of x and y is 72.

`x+y=72 \ \ \ |-y \\ x=72-y`

Set both expressions equal to each other:

`x=x \\ (3)/(5)y=72-y \ \ \ |* 5 \\ 3y=360-5y \ \ \ |+5y \\ 8y=360 \ \ \ |/ 8 \\ y=45 \\ \\ x=72-y=72-45=27`

72 divided in a ratio of 3:5 is 27:45.