A packet contained brown, purple and pink pens.
25 of the pens were brown and
49 of the remainder were purple pens.The rest were pink pens.
- Find the ratio of the number of pink pens to the number of brown pens.
- There were 144 fewer purple pens than brown pens. How many pens were there in the packet?
| Brown pens |
Purple pens |
Pink pens |
| 2x3 |
3x3 |
| |
4x1 |
5x1 |
| 6 u |
4 u |
5 u |
(a)
Fraction of brown pens =
25 Fraction of pens that are not brown = 1 -
25 =
35Remaining fraction of purple pens =
49Remaining fraction of pink pens = 1 -
49 =
59The total number of purple pens and pink pens is the repeated identity.
Make the repeated identity the same by using LCM.
LCM of 3 and 9 = 9
Pink pens : Brown pens
5 : 6
(b)
Difference in the number of brown pens and purple pens
= 6 u - 4 u
= 2 u
2 u = 144
1 u = 144 ÷ 2 = 72
Total number of pens
= 6 u + 4 u + 5 u
= 15 u
= 15 x 72
= 1080
Answer(s): (a) 5 : 6; (b) 1080
