Betty had 100 crayons.
34 of them were black crayons and the rest were purple crayons. After she had given away some black crayons, the ratio of the number of black crayons to the number of purple crayons became 3 : 5. How many crayons did she have in the end?
| |
Black |
Purple |
Total |
| Before |
3x5 =
15 u |
1x5 =
5 u |
4x5 =
20 u |
| Change |
- 12 u |
|
|
| After |
3 u |
5 u |
8 u |
The number of purple crayons remained unchanged.
LCM of 1 and 5 = 5
Total number of crayons at first = 20 u
20 u = 100
1 u = 100 ÷ 20 = 5
Number of crayons that Betty had in the end
= 3 u + 5 u
= 8 u
= 8 x 5
= 40
Answer(s):40
