Mrs Ee is 51 years old and her son is 7 years old now. In how many years' time will Mrs Ee be thrice as old as her son?
| |
Mrs Ee |
Her son |
Difference |
| Before |
51 |
7 |
44 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the age between Mrs Ee and her son remains unchanged.
Difference in their age at first
= 51 - 7
= 44
Difference in their age in the end
= 3 u - 1 u
= 2 u
2 u = 44
1 u = 44 ÷ 2 = 22
Number of years time that Mrs Ee will be thrice as old as her son
= 1 u - 7
= 22 - 7
= 15
Answer(s): 15
