In April, Esther and Ian had erasers in the ratio 7 : 4. In May, each of them gave away the same number of erasers. Esther then had thrice as many erasers as Ian.
- Find the ratio of the number of erasers Ian had in April to the number of erasers he had in May.
- Find the ratio of the total number of erasers both had in April to the total number of erasers both had in May.
| |
Esther |
Ian |
Difference |
| Before |
7x2 =
14 u |
4x2 =
8 u |
3x2 =
6 u |
| Change |
- 5 u |
- 5 u |
|
| After |
3x3 =
9 u |
1x3 =
3 u |
2x3 =
6 u |
(a)
Since Esther and Ian gave away the same number of erasers, the difference in the number of erasers between Esther and Ian 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 3 and 2 is 6.
Ian's erasers in April : Ian's erasers in May
8 : 3
(b)
Total number of erasers in April
= 14 u + 8 u
= 22 u
Total number of erasers in May
= 9 u + 3 u
= 12 u
Total erasers in April : Total erasers in May
22 : 12
(÷2)11 : 6
Answer(s): (a) 8 : 3; (b) 11 : 6
