In March, Wendy and Michael had pens in the ratio 9 : 7. In April, each of them gave away the same number of pens. Wendy then had twice as many pens as Michael.
- Find the ratio of the number of pens Michael had in March to the number of pens he had in April.
- Find the ratio of the total number of pens both had in March to the total number of pens both had in April.
| |
Wendy |
Michael |
Difference |
| Before |
9x1 =
9 u |
7x1 =
7 u |
2x1 =
2 u |
| Change |
- 5 u |
- 5 u |
|
| After |
2x2 =
4 u |
1x2 =
2 u |
1x2 =
2 u |
(a)
Since Wendy and Michael gave away the same number of pens, the difference in the number of pens between Wendy and Michael 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 2 and 1 is 2.
Michael's pens in March : Michael's pens in April
7 : 2
(b)
Total number of pens in March
= 9 u + 7 u
= 16 u
Total number of pens in April
= 4 u + 2 u
= 6 u
Total pens in March : Total pens in April
16 : 6
(÷2)8 : 3
Answer(s): (a) 7 : 2; (b) 8 : 3
