Justin is 7 years old. His uncle is 36 years older than him. In how many years will Justin's uncle be 4 times as old as Justin?
|
His uncle |
Justin |
Difference |
Before |
43 |
7 |
36 |
Change |
+ ? |
+ ? |
|
After |
4 u |
1 u |
3 u |
The difference in the age between Justin and his uncle at first and in the end remains the same.
Difference in the age between Justin and his uncle
= 4 u - 1 u
= 3 u
3 u = 36
1 u = 36 ÷ 3 = 12
The increase in age of Justin and his uncle remains the same.
Number of years' time so Justin's uncle will be 4 times as old as Justin
= 12 - 7
= 5
Answer(s): 5