Tammy has a bag containing some red and green erasers. If she removes 8 red erasers, 25% of the erasers in the bag are green. If she removes another 10 green erasers, 10% of the erasers in the bag are green. How many red erasers are in the bag?
| |
Red erasers |
Green erasers |
| Before |
9 u + 8 |
3 u |
| Change 1 |
- 8 |
|
| After 1 |
3x3 =
9 u |
1x3 =
3 u |
| Change 2 |
|
- 10 |
| After 2 |
9x1 =
9 u |
1x1 =
1 u |
25% =
25100 =
1410% =
10100 =
110The number of red erasers remains unchanged at the second change when she removes another 10 green erasers. Make the number of red erasers the same at the second change. LCM of 3 and 9 is 9.
Number of green erasers removed
= 3 u - 1 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Number of red erasers at first
= 9 u + 8
= 9 x 5 + 8
= 45 + 8
= 53
Answer(s): 53
