Yoko had 120 pencils.
910 of them were pink pencils and the rest were red pencils. After she had given away some pink pencils, the ratio of the number of pink pencils to the number of red pencils became 3 : 4. How many pink pencils did she give away?
| |
Pink |
Red |
Total |
| Before |
9x4 =
36 u |
1x4 =
4 u |
10x4 =
40 u |
| Change |
- 33 u |
|
|
| After |
3 u |
4 u |
7 u |
The number of red pencils remained unchanged.
LCM of 1 and 4 = 4
Total number of pencils at first = 40 u
40 u = 120
1 u = 120 ÷ 40 = 3
Number of pink pencils that she gave away
= 36 u - 3 u
= 33 u
= 33 x 3
= 99
Answer(s):99
