Eva had some eraser collection.
12 of them were silver and the rest were yellow. She gave away 180 of the yellow erasers and 30% of the silver erasers. She then had
14 of her eraser collection left. How many erasers did Eva give away?
| |
Silver |
Yellow |
Total |
Total |
Before
|
1x2 =
2 u |
1x2 =
2 u |
2x2 =
4 u |
4x1 =
4 u |
Change
|
- 0.3x2 =
- 0.6 u |
- 180 |
|
- 3x1 =
- 3 u |
After
|
0.7x2 =
1.4 u |
2 u - 180 |
|
1x1 =
1 u |
The total number of erasers that Eva had at first is repeated. Make the total number of erasers at first the same. LCM 2 and 4 is 4.
Number of silver erasers that Eva gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
0.6 u - 180 = 3 u
3 u - 0.6 u = 180
2.4 u = 180
1 u = 180 ÷ 2.4 = 75
Number of erasers that Eva gave away
= 3 u
= 3 x 75
= 225
Answer(s): 225
