George's father is 5 times as old as him. His father will be 34 years old in 9 years' time. In how many years' time will George's age be 75% that of his father's?
| |
George's father |
George |
Difference |
Before
(now) |
5x1 =
5 u |
1x1 =
1 u |
4x1 =
4 u |
| Change 1 |
+ 9 |
+ 9 |
|
| After 1 |
34 |
|
|
| Change 2 |
+ ? |
+ ? |
|
| After 2 |
4x4 =
16 u |
3x4 =
12 u |
1x4 =
4 u |
75% =
75100 =
34 George's father : George = 4 : 3
The difference in age between George's father and George always remains the same. Make the difference in age between George's father and George the same. LCM of 4 and 1 is 4.
5 u + 9 = 34
5 u = 34 - 9
5 u = 25
1 u = 25 ÷ 5 = 5
Number of years' time when George's age will be 75% that of his father's
= 16 u - 34
= 16 x 5 - 34
= 80 - 34
= 46
Answer(s): 46
