Barbara had some black coins and gold coins in 2 packets. In Packet C, the ratio of the number of black coins to gold coins was 8 : 5. In Packet D, the number of black coins was 2 times the number of gold coins. Barbara transferred
25 of the gold coins from Packet C to Packet D. The number of coins in Packet C became 44 and the ratio of the number of black coins to gold coins in Packet D became 6 : 7.
- How many gold coins were transferred from Packet C to Packet D?
- What was the number of coins in Packet D after the transfer?
|
Packet C |
Packet D |
|
Black |
Gold |
Black |
Gold |
Comparing black coins and gold coins at first |
8 u |
5 u |
2x3 = 6 p |
1x3 = 3 p |
Before |
|
5 u |
|
|
Change |
|
- 2 u |
|
+ 2 u |
After |
|
3 u |
|
|
Comparing black coins and gold coins in the end |
8 u |
3 u |
6 p |
7 p |
(a)
Total number of coins in the end for Packet C
= 8 u + 3 u
= 11 u
11 u = 44
1 u = 44 ÷ 11 = 4
Number of gold coins that were transferred from Packet C to Packet D
= 2 u
= 2 x 4
= 8
(b)
The number of black coins in Packet D remains unchanged. Make the number of black coins in Packet D the same. LCM of 2 and 6 is 6.
Increase in the number of gold coins in Packet D
= 7 p - 3 p
= 4 p
4 p = 2 u
4 p = 8
1 p = 8 ÷ 4 = 2
Number of coins in Packet D in the end
= 6 p + 7 p
= 13 p
= 13 x 2
= 26
Answer(s): (a) 8; (b) 26