Question

The sum of a number and $\frac{1}{3}$ of the number is $40$. Find the number ?

Answer 1

Let x=one of the numbers

then from "One number is $\frac{1}{3}$ of another number."we have $\frac{1}{3}x$=second number

$x+\frac{1}{3}x=40$

multiply both sides by 3:

$3x+x=120$

$4x=120$

$x=30$

Second number: $\frac{1}{3}x=\frac{1}{3}30=\left(1\right)10=10.$