In January, Winnie and Luis had stamps in the ratio 11 : 9. In February, each of them gave away the same number of stamps. Winnie then had five times as many stamps as Luis.
- Find the ratio of the number of stamps Luis had in January to the number of stamps he had in February.
- Find the ratio of the total number of stamps both had in January to the total number of stamps both had in February.
| |
Winnie |
Luis |
Difference |
| Before |
11x2 =
22 u |
9x2 =
18 u |
2x2 =
4 u |
| Change |
- 17 u |
- 17 u |
|
| After |
5x1 =
5 u |
1x1 =
1 u |
4x1 =
4 u |
(a)
Since Winnie and Luis gave away the same number of stamps, the difference in the number of stamps between Winnie and Luis at first and in the end remains the same.
Make the difference in the number of stamps at first and in the end the same. LCM of 2 and 4 is 4.
Luis's stamps in January : Luis's stamps in February
18 : 1
(b)
Total number of stamps in January
= 22 u + 18 u
= 40 u
Total number of stamps in February
= 5 u + 1 u
= 6 u
Total stamps in January : Total stamps in February
40 : 6
(÷2)20 : 3
Answer(s): (a) 18 : 1; (b) 20 : 3
