Kylie is 4 years old. Her aunt is 40 years old. How old will Kylie be when her aunt is four times her age?
| |
Kylie |
Her aunt |
Difference |
| Before |
4 |
40 |
36 |
| Change |
+ ? |
+ ? |
|
| After |
1 u |
4 u |
3 u |
The difference in the age between Kylie and her aunt remains unchanged.
Difference in their age at first
= 40 - 4
= 36
Difference in their age in the end
= 4 u - 1 u
= 3 u
3 u = 36
1 u = 36 ÷ 3 = 12
Kylie's age when her aunt is four times her age
= 1 u
= 12
Answer(s): 12
