Cindy had some purple beads and blue beads in 2 bags. In Bag X, the ratio of the number of purple beads to blue beads was 10 : 3. In Bag Y, the number of purple beads was 2 times the number of blue beads. Cindy transferred
23 of the blue beads from Bag X to Bag Y. The number of beads in Bag X became 66 and the ratio of the number of purple beads to blue beads in Bag Y became 4 : 5.
- How many blue beads were transferred from Bag X to Bag Y?
- What was the number of beads in Bag Y after the transfer?
|
Bag X |
Bag Y |
|
Purple |
Blue |
Purple |
Blue |
Comparing purple beads and blue beads at first |
10 u |
3 u |
2x2 = 4 p |
1x2 = 2 p |
Before |
|
3 u |
|
|
Change |
|
- 2 u |
|
+ 2 u |
After |
|
1 u |
|
|
Comparing purple beads and blue beads in the end |
10 u |
1 u |
4 p |
5 p |
(a)
Total number of beads in the end for Bag X
= 10 u + 1 u
= 11 u
11 u = 66
1 u = 66 ÷ 11 = 6
Number of blue beads that were transferred from Bag X to Bag Y
= 2 u
= 2 x 6
= 12
(b)
The number of purple beads in Bag Y remains unchanged. Make the number of purple beads in Bag Y the same. LCM of 2 and 4 is 4.
Increase in the number of blue beads in Bag Y
= 5 p - 2 p
= 3 p
3 p = 2 u
3 p = 12
1 p = 12 ÷ 3 = 4
Number of beads in Bag Y in the end
= 4 p + 5 p
= 9 p
= 9 x 4
= 36
Answer(s): (a) 12; (b) 36