Tiffany has a bag containing some pink and green coins. If she adds in 5 pink coins, 20% of the coins in the bag are green. If she adds in another 50 green coins, 60% of the coins in the bag are green. How many pink coins are in the bag?
| |
Pink coins |
Green coins |
| Before |
4 u - 5 |
1 u |
| Change 1 |
+ 5 |
|
| After 1 |
4x1 =
4 u |
1x1 =
1 u |
| Change 2 |
|
+ 50 |
| After 2 |
2x2 =
4 u |
3x2 =
6 u |
20% =
20100 =
1560% =
60100 =
35The number of pink coins remains unchanged at the second change when she adds in another 50 green coins. Make the number of pink coins the same at the second change. LCM of 4 and 2 is 4.
Number of green coins added
= 6 u - 1 u
= 5 u
5 u = 50
1 u = 50 ÷ 5 = 10
Number of pink coins at first
= 4 u - 5
= 4 x 10 - 5
= 40 - 5
= 35
Answer(s): 35
