Ivan's mother is 5 times as old as him. His mother will be 48 years old in 8 years' time. In how many years' time will Ivan's age be 60% that of his mother's?
| |
Ivan's mother |
Ivan |
Difference |
Before
(now) |
5x1 =
5 u |
1x1 =
1 u |
4x1 =
4 u |
| Change 1 |
+ 8 |
+ 8 |
|
| After 1 |
48 |
|
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
5x2 =
10 u |
3x2 =
6 u |
2x2 =
4 u |
60% =
60100 =
35 Ivan's mother : Ivan = 5 : 3
The difference in age between Ivan's mother and Ivan always remains the same. Make the difference in age between Ivan's mother and Ivan the same. LCM of 4 and 2 is 4.
5 u + 8 = 48
5 u = 48 - 8
5 u = 40
1 u = 40 ÷ 5 = 8
Number of years' time when Ivan's age will be 60% that of his mother's
= 10 u - 48
= 10 x 8 - 48
= 80 - 48
= 32
Answer(s): 32
