Sarah has a bag containing some red and green stickers. If she removes 5 red stickers, 20% of the stickers in the bag are green. If she adds another 45 green stickers, 30% of the stickers in the bag are green. How many red stickers are in the bag?
| |
Red stickers |
Green stickers |
| Before |
28 u + 5 |
7 u |
| Change 1 |
- 5 |
|
| After 1 |
4x7 =
28 u |
1x7 =
7 u |
| Change 2 |
|
+ 45 |
| After 2 |
7x4 =
28 u |
3x4 =
12 u |
20% =
20100 =
1530% =
30100 =
310The number of red stickers remains unchanged at the second change when she adds another 45 green stickers. Make the number of red stickers the same at the second change. LCM of 4 and 7 is 28.
Number of green stickers added
= 12 u - 7 u
= 5 u
5 u = 45
1 u = 45 ÷ 5 = 9
Number of red stickers at first
= 28 u + 5
= 28 x 9 + 5
= 252 + 5
= 257
Answer(s): 257
