Natalie has a bag containing some red and orange stamps. If she removes 10 red stamps, 10% of the stamps in the bag are orange. If she adds another 30 orange stamps, 20% of the stamps in the bag are orange. How many red stamps are in the bag?
| |
Red stamps |
Orange stamps |
| Before |
36 u + 10 |
4 u |
| Change 1 |
- 10 |
|
| After 1 |
9x4 =
36 u |
1x4 =
4 u |
| Change 2 |
|
+ 30 |
| After 2 |
4x9 =
36 u |
1x9 =
9 u |
10% =
10100 =
11020% =
20100 =
15The number of red stamps remains unchanged at the second change when she adds another 30 orange stamps. Make the number of red stamps the same at the second change. LCM of 9 and 4 is 36.
Number of orange stamps added
= 9 u - 4 u
= 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Number of red stamps at first
= 36 u + 10
= 36 x 6 + 10
= 216 + 10
= 226
Answer(s): 226
