Eva had some card collection.
12 of them were purple and the rest were red. She gave away 124 of the red cards and 30% of the purple cards. She then had
13 of her card collection left. How many cards did Eva give away?
| |
Purple |
Red |
Total |
Total |
Before
|
1x3 =
3 u |
1x3 =
3 u |
2x3 =
6 u |
3x2 =
6 u |
Change
|
- 0.3x3 =
- 0.9 u |
- 124 |
|
- 2x2 =
- 4 u |
After
|
0.7x3 =
2.1 u |
3 u - 124 |
|
1x2 =
2 u |
The total number of cards that Eva had at first is repeated. Make the total number of cards at first the same. LCM 2 and 3 is 6.
Number of purple cards that Eva gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
0.9 u - 124 = 4 u
4 u - 0.9 u = 124
3.1 u = 124
1 u = 124 ÷ 3.1 = 40
Number of cards that Eva gave away
= 4 u
= 4 x 40
= 160
Answer(s): 160
