Marion was 7 years old last year. She was 22 years younger than Xandra.
- How old will her Xandra be 7 years later?
- In how many years' time will Marion's age be 13 of Xandra's age?
| |
Marion |
Xandra |
Difference |
| Before (Last year) |
7 |
29 |
22 |
| Change 1 |
+ 1 |
+ 1 |
|
| After 1 (Now) |
8 |
30 |
22 |
| Change 2 |
+ 7 |
+ 7 |
|
| After 2 (7 years later) |
|
? |
22 |
(a)
Xandra's age this year
= 7 + 22
= 29
Xandra's age this year
= 29 + 1
= 30
Xandra's age in 7 years' time
= 30 + 7
= 37
| |
Marion |
Xandra |
Difference |
| Before |
8 |
30 |
22 |
| Change |
+ ? |
+ ? |
|
| After |
1 u |
3 u |
2 u |
(b)
The difference in the age between Marion and Xandra at first and in the end remains unchanged.
Difference in the age between Marion and Xandra
= 3 u - 1 u
= 2 u
2 u = 22
1 u = 22 ÷ 2 = 11
Number of years' time that Marion's age be
13 of Xandra's age
= 11 - 8
= 3
Answer(s): (a) 37; (b) 3
