Irene had some stamp collection.
23 of them were blue and the rest were red. She gave away 133 of the red stamps and 30% of the blue stamps. She then had
16 of her stamp collection left. How many stamps did Irene give away?
| |
Blue |
Red |
Total |
Total |
Before
|
2x2 =
4 u |
1x2 =
2 u |
3x2 =
6 u |
6x1 =
6 u |
Change
|
- 0.6x2 =
- 1.2 u |
- 133 |
|
- 5x1 =
- 5 u |
After
|
1.4x2 =
2.8 u |
2 u - 133 |
|
1x1 =
1 u |
The total number of stamps that Irene had at first is repeated. Make the total number of stamps at first the same. LCM 3 and 6 is 6.
Number of blue stamps that Irene gave away
= 30% x 2 u
=
30100 x 2 u
= 0.6 u
1.2 u - 133 = 5 u
5 u - 1.2 u = 133
3.8 u = 133
1 u = 133 ÷ 3.8 = 35
Number of stamps that Irene gave away
= 5 u
= 5 x 35
= 175
Answer(s): 175
