Fanny has a bag containing some pink and green erasers. If she adds in 16 pink erasers, 10% of the erasers in the bag are green. If she adds in another 72 green erasers, 50% of the erasers in the bag are green. How many pink erasers are in the bag?
| |
Pink erasers |
Green erasers |
| Before |
9 u - 16 |
1 u |
| Change 1 |
+ 16 |
|
| After 1 |
9x1 =
9 u |
1x1 =
1 u |
| Change 2 |
|
+ 72 |
| After 2 |
1x9 =
9 u |
1x9 =
9 u |
10% =
10100 =
11050% =
50100 =
12The number of pink erasers remains unchanged at the second change when she adds in another 72 green erasers. Make the number of pink erasers the same at the second change. LCM of 9 and 1 is 9.
Number of green erasers added
= 9 u - 1 u
= 8 u
8 u = 72
1 u = 72 ÷ 8 = 9
Number of pink erasers at first
= 9 u - 16
= 9 x 9 - 16
= 81 - 16
= 65
Answer(s): 65
