Betty had 150 pencils.
45 of them were green pencils and the rest were yellow pencils. After she had given away some green pencils, the ratio of the number of green pencils to the number of yellow pencils became 3 : 5. How many green pencils did she give away?
| |
Green |
Yellow |
Total |
| Before |
4x5 =
20 u |
1x5 =
5 u |
5x5 =
25 u |
| Change |
- 17 u |
|
|
| After |
3 u |
5 u |
8 u |
The number of yellow pencils remained unchanged.
LCM of 1 and 5 = 5
Total number of pencils at first = 25 u
25 u = 150
1 u = 150 ÷ 25 = 6
Number of green pencils that she gave away
= 20 u - 3 u
= 17 u
= 17 x 6
= 102
Answer(s):102
