Tina has a bag containing some pink and gold stamps. If she removes 16 pink stamps, 20% of the stamps in the bag are gold. If she adds another 55 gold stamps, 30% of the stamps in the bag are gold. How many pink stamps are in the bag?
| |
Pink stamps |
Gold stamps |
| Before |
28 u + 16 |
7 u |
| Change 1 |
- 16 |
|
| After 1 |
4x7 =
28 u |
1x7 =
7 u |
| Change 2 |
|
+ 55 |
| After 2 |
7x4 =
28 u |
3x4 =
12 u |
20% =
20100 =
1530% =
30100 =
310The number of pink stamps remains unchanged at the second change when she adds another 55 gold stamps. Make the number of pink stamps the same at the second change. LCM of 4 and 7 is 28.
Number of gold stamps added
= 12 u - 7 u
= 5 u
5 u = 55
1 u = 55 ÷ 5 = 11
Number of pink stamps at first
= 28 u + 16
= 28 x 11 + 16
= 308 + 16
= 324
Answer(s): 324
