Diana is 3 years old. Her uncle is 33 years old. How old will Diana be when her uncle is three times her age?
| |
Diana |
Her uncle |
Difference |
| Before |
3 |
33 |
30 |
| Change |
+ ? |
+ ? |
|
| After |
1 u |
3 u |
2 u |
The difference in the age between Diana and her uncle remains unchanged.
Difference in their age at first
= 33 - 3
= 30
Difference in their age in the end
= 3 u - 1 u
= 2 u
2 u = 30
1 u = 30 ÷ 2 = 15
Diana's age when her uncle is three times her age
= 1 u
= 15
Answer(s): 15
