Mrs Lau is 48 years old and her nephew is 8 years old now. In how many years' time will Mrs Lau be five times as old as her nephew?
| |
Mrs Lau |
Her nephew |
Difference |
| Before |
48 |
8 |
40 |
| Change |
+ ? |
+ ? |
|
| After |
5 u |
1 u |
4 u |
The difference in the age between Mrs Lau and her nephew remains unchanged.
Difference in their age at first
= 48 - 8
= 40
Difference in their age in the end
= 5 u - 1 u
= 4 u
4 u = 40
1 u = 40 ÷ 4 = 10
Number of years time that Mrs Lau will be five times as old as her nephew
= 1 u - 8
= 10 - 8
= 2
Answer(s): 2
