Wendy was 9 years old last year. She was 22 years younger than Shannon.
- How old will her Shannon be 7 years later?
- In how many years' time will Wendy's age be 13 of Shannon's age?
|
Wendy |
Shannon |
Difference |
Before (Last year) |
9 |
31 |
22 |
Change 1 |
+ 1 |
+ 1 |
|
After 1 (Now) |
10 |
32 |
22 |
Change 2 |
+ 7 |
+ 7 |
|
After 2 (7 years later) |
|
? |
22 |
(a)
Shannon's age this year
= 9 + 22
= 31
Shannon's age this year
= 31 + 1
= 32
Shannon's age in 7 years' time
= 32 + 7
= 39
|
Wendy |
Shannon |
Difference |
Before |
10 |
32 |
22 |
Change |
+ ? |
+ ? |
|
After |
1 u |
3 u |
2 u |
(b)
The difference in the age between Wendy and Shannon at first and in the end remains unchanged.
Difference in the age between Wendy and Shannon
= 3 u - 1 u
= 2 u
2 u = 22
1 u = 22 ÷ 2 = 11
Number of years' time that Wendy's age be
13 of Shannon's age
= 11 - 10
= 1
Answer(s): (a) 39; (b) 1