Betty has a bag containing some pink and orange coins. If she removes 16 pink coins, 20% of the coins in the bag are orange. If she adds another 60 orange coins, 30% of the coins in the bag are orange. How many pink coins are in the bag?
| |
Pink coins |
Orange coins |
| Before |
28 u + 16 |
7 u |
| Change 1 |
- 16 |
|
| After 1 |
4x7 =
28 u |
1x7 =
7 u |
| Change 2 |
|
+ 60 |
| After 2 |
7x4 =
28 u |
3x4 =
12 u |
20% =
20100 =
1530% =
30100 =
310The number of pink coins remains unchanged at the second change when she adds another 60 orange coins. Make the number of pink coins the same at the second change. LCM of 4 and 7 is 28.
Number of orange coins added
= 12 u - 7 u
= 5 u
5 u = 60
1 u = 60 ÷ 5 = 12
Number of pink coins at first
= 28 u + 16
= 28 x 12 + 16
= 336 + 16
= 352
Answer(s): 352
