Yoko has a bag containing some pink and yellow stamps. If she removes 19 pink stamps, 30% of the stamps in the bag are yellow. If she adds another 16 yellow stamps, 50% of the stamps in the bag are yellow. How many pink stamps are in the bag?
| |
Pink stamps |
Yellow stamps |
| Before |
7 u + 19 |
3 u |
| Change 1 |
- 19 |
|
| After 1 |
7x1 =
7 u |
3x1 =
3 u |
| Change 2 |
|
+ 16 |
| After 2 |
1x7 =
7 u |
1x7 =
7 u |
30% =
30100 =
31050% =
50100 =
12The number of pink stamps remains unchanged at the second change when she adds another 16 yellow stamps. Make the number of pink stamps the same at the second change. LCM of 7 and 1 is 7.
Number of yellow stamps added
= 7 u - 3 u
= 4 u
4 u = 16
1 u = 16 ÷ 4 = 4
Number of pink stamps at first
= 7 u + 19
= 7 x 4 + 19
= 28 + 19
= 47
Answer(s): 47
