Mrs Ang is 53 years old and her son is 11 years old now. In how many years' time will Mrs Ang be four times as old as her son?
|
Mrs Ang |
Her son |
Difference |
Before |
53 |
11 |
42 |
Change |
+ ? |
+ ? |
|
After |
4 u |
1 u |
3 u |
The difference in the age between Mrs Ang and her son remains unchanged.
Difference in their age at first
= 53 - 11
= 42
Difference in their age in the end
= 4 u - 1 u
= 3 u
3 u = 42
1 u = 42 ÷ 3 = 14
Number of years time that Mrs Ang will be four times as old as her son
= 1 u - 11
= 14 - 11
= 3
Answer(s): 3