Rachel had 125 pens.
45 of them were yellow pens and the rest were red pens. After she had given away some yellow pens, the ratio of the number of yellow pens to the number of red pens became 3 : 5. How many yellow pens did she give away?
| |
Yellow |
Red |
Total |
| Before |
4x5 =
20 u |
1x5 =
5 u |
5x5 =
25 u |
| Change |
- 17 u |
|
|
| After |
3 u |
5 u |
8 u |
The number of red pens remained unchanged.
LCM of 1 and 5 = 5
Total number of pens at first = 25 u
25 u = 125
1 u = 125 ÷ 25 = 5
Number of yellow pens that she gave away
= 20 u - 3 u
= 17 u
= 17 x 5
= 85
Answer(s):85
