Ivan is 2 years old now. His sister is 30 years older than him. How old will Ivan be when his age is
38 of his sister's age?
| |
Ivan |
His sister |
Difference |
| Before |
|
|
30 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
8 u |
5 u |
The difference in the age between Ivan and his sister at first and in the end remains unchanged.
Number of years that his sister is older than Ivan
= 8 u - 3 u
= 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Ivan's age when his age is
38 of his sister's age
= 3 u
= 3 x 6
= 18
Answer(s): 18
