Zara was 11 years old last year. She was 28 years younger than Wendy.
- How old will her Wendy be 3 years later?
- In how many years' time will Zara's age be 13 of Wendy's age?
|
Zara |
Wendy |
Difference |
Before (Last year) |
11 |
39 |
28 |
Change 1 |
+ 1 |
+ 1 |
|
After 1 (Now) |
12 |
40 |
28 |
Change 2 |
+ 3 |
+ 3 |
|
After 2 (3 years later) |
|
? |
28 |
(a)
Wendy's age this year
= 11 + 28
= 39
Wendy's age this year
= 39 + 1
= 40
Wendy's age in 3 years' time
= 40 + 3
= 43
|
Zara |
Wendy |
Difference |
Before |
12 |
40 |
28 |
Change |
+ ? |
+ ? |
|
After |
1 u |
3 u |
2 u |
(b)
The difference in the age between Zara and Wendy at first and in the end remains unchanged.
Difference in the age between Zara and Wendy
= 3 u - 1 u
= 2 u
2 u = 28
1 u = 28 ÷ 2 = 14
Number of years' time that Zara's age be
13 of Wendy's age
= 14 - 12
= 2
Answer(s): (a) 43; (b) 2