On Chris' birthday in 1992, he was half the age of his brother Joseph. On Chris' birthday in 1998, he was two-thirds the age of Joseph. How old will Chris be on his birthday in 2018?
Step 1: Form an equation.
We know that in 1992, Chris was HALF the age of Joseph. So Chris was x years old, while his brother was twice his age, or 2x. 6 years later, he was two-thirds the age of his brother. So, he was (x+6) while his brother was (2x+6).
So, we can form this:
(X+6)=(2/3)(2x+6)
Step 2: Simplify the equation. Distribute, Subtract, multiply
(X+6)=(2/3)(2x+6)
Distribute: X+6=(2/3)(2x)+(2/3)(6)
X+6=4/3x+4
Subtract:
X+6-4/3x=4/3x+4-4/3x
-1/3x+6=4
Subtract:
-1/3x+6-6=4-6
1/3x=-2
Multiply:
(3/-1) * (-1/3x)=(3/-1)*(-2)
X=6
This means in 1992, Chris was indeed 6 years old, while his brother was 12. 6 years later, Chris was 12 years old, while his brother was 18. (6/12=1/2; 12/18=2/3)
So, from 1992-2018=26 years.
In 1992 Chris was already 6.
26+6=32
In 2018, Chris is 32 years old, his brother is 6 years older, 38.
Chris is 32 years old.
~Hope this helps!
