Betty had 132 pens.
23 of them were grey pens and the rest were yellow pens. After she had given away some grey pens, the ratio of the number of grey pens to the number of yellow pens became 3 : 4. How many pens did she have in the end?
| |
Grey |
Yellow |
Total |
| Before |
2x4 =
8 u |
1x4 =
4 u |
3x4 =
12 u |
| Change |
- 5 u |
|
|
| After |
3 u |
4 u |
7 u |
The number of yellow pens remained unchanged.
LCM of 1 and 4 = 4
Total number of pens at first = 12 u
12 u = 132
1 u = 132 ÷ 12 = 11
Number of pens that Betty had in the end
= 3 u + 4 u
= 7 u
= 7 x 11
= 77
Answer(s):77
