Question

One number is 3 times more than another number. Their sum is 20. What are the two numbers?

Answer 1

n+3n=20

4n=20

Divide both sides by 4

n=5

5+(3*5)=20

5+15=20

NUMBERS ARE  5 and 15

Answer 2

3x=y
X+Y=20
5=x and 15=y are the answer. You can use elimination or substitution or guess and check!