Billy is 5 years old. His uncle is 38 years older than him. In how many years will Billy's uncle be 3 times as old as Billy?
| |
His uncle |
Billy |
Difference |
| Before |
43 |
5 |
38 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Billy and his uncle at first and in the end remains the same.
Difference in the age between Billy and his uncle
= 3 u - 1 u
= 2 u
2 u = 38
1 u = 38 ÷ 2 = 19
The increase in age of Billy and his uncle remains the same.
Number of years' time so Billy's uncle will be 3 times as old as Billy
= 19 - 5
= 14
Answer(s): 14
