Abi had 144 pens.
23 of them were purple pens and the rest were blue pens. After she had given away some purple pens, the ratio of the number of purple pens to the number of blue pens became 5 : 6. How many purple pens did she give away?
|
Purple |
Blue |
Total |
Before |
2x6 = 12 u |
1x6 = 6 u |
3x6 = 18 u |
Change |
- 7 u |
|
|
After |
5 u |
6 u |
11 u |
The number of blue pens remained unchanged.
LCM of 1 and 6 = 6
Total number of pens at first = 18 u
18 u = 144
1 u = 144 ÷ 18 = 8
Number of purple pens that she gave away
= 12 u - 5 u
= 7 u
= 7 x 8
= 56
Answer(s):56