In February, Ivory and Mark had pens in the ratio 3 : 2. In March, each of them gave away the same number of pens. Ivory then had five times as many pens as Mark.
- Find the ratio of the number of pens Mark had in February to the number of pens he had in March.
- Find the ratio of the total number of pens both had in February to the total number of pens both had in March.
| |
Ivory |
Mark |
Difference |
| Before |
3x4 =
12 u |
2x4 =
8 u |
1x4 =
4 u |
| Change |
- 7 u |
- 7 u |
|
| After |
5x1 =
5 u |
1x1 =
1 u |
4x1 =
4 u |
(a)
Since Ivory and Mark gave away the same number of pens, the difference in the number of pens between Ivory and Mark at first and in the end remains the same.
Make the difference in the number of pens at first and in the end the same. LCM of 1 and 4 is 4.
Mark's pens in February : Mark's pens in March
8 : 1
(b)
Total number of pens in February
= 12 u + 8 u
= 20 u
Total number of pens in March
= 5 u + 1 u
= 6 u
Total pens in February : Total pens in March
20 : 6
(÷2)10 : 3
Answer(s): (a) 8 : 1; (b) 10 : 3
