Question

Alvin’s age is three times Elga’s age. The sum of their ages is 20. What is Elga’s age?

Answer 1

A = Alvin's age
E = Elga's age

Given:

A = 2E
A + E = 48

Just solve the 2 equations above. Plug A = 2E into the bottom equation and get

2E + E = 48
E = 48/3 = 16

Then A = 2E = 2*16 = 32

Alvin is 32, Elga is 16.

Answer 2

Elga's age is 5.

Explanation:

3x=y

x+y=20

-------------

x+3x=20

4x=20

x=20/4

x=5

3(5)=15

y=15

x=5, y=15