Ivory was 10 years old last year. She was 28 years younger than Kimberly.
- How old will her Kimberly be 3 years later?
- In how many years' time will Ivory's age be 13 of Kimberly's age?
| |
Ivory |
Kimberly |
Difference |
| Before (Last year) |
10 |
38 |
28 |
| Change 1 |
+ 1 |
+ 1 |
|
| After 1 (Now) |
11 |
39 |
28 |
| Change 2 |
+ 3 |
+ 3 |
|
| After 2 (3 years later) |
|
? |
28 |
(a)
Kimberly's age this year
= 10 + 28
= 38
Kimberly's age this year
= 38 + 1
= 39
Kimberly's age in 3 years' time
= 39 + 3
= 42
| |
Ivory |
Kimberly |
Difference |
| Before |
11 |
39 |
28 |
| Change |
+ ? |
+ ? |
|
| After |
1 u |
3 u |
2 u |
(b)
The difference in the age between Ivory and Kimberly at first and in the end remains unchanged.
Difference in the age between Ivory and Kimberly
= 3 u - 1 u
= 2 u
2 u = 28
1 u = 28 ÷ 2 = 14
Number of years' time that Ivory's age be
13 of Kimberly's age
= 14 - 11
= 3
Answer(s): (a) 42; (b) 3
