In February, Nora and Perry had erasers in the ratio 3 : 2. In March, each of them gave away the same number of erasers. Nora then had four times as many erasers as Perry.
- Find the ratio of the number of erasers Perry had in February to the number of erasers he had in March.
- Find the ratio of the total number of erasers both had in February to the total number of erasers both had in March.
| |
Nora |
Perry |
Difference |
| Before |
3x3 =
9 u |
2x3 =
6 u |
1x3 =
3 u |
| Change |
- 5 u |
- 5 u |
|
| After |
4x1 =
4 u |
1x1 =
1 u |
3x1 =
3 u |
(a)
Since Nora and Perry gave away the same number of erasers, the difference in the number of erasers between Nora and Perry at first and in the end remains the same.
Make the difference in the number of erasers at first and in the end the same. LCM of 1 and 3 is 3.
Perry's erasers in February : Perry's erasers in March
6 : 1
(b)
Total number of erasers in February
= 9 u + 6 u
= 15 u
Total number of erasers in March
= 4 u + 1 u
= 5 u
Total erasers in February : Total erasers in March
15 : 5
(÷5)3 : 1
Answer(s): (a) 6 : 1; (b) 3 : 1
