Lucy had some stamp collection.
23 of them were blue and the rest were red. She gave away 111 of the red stamps and 20% of the blue stamps. She then had
14 of her stamp collection left. How many stamps did Lucy give away?
| |
Blue |
Red |
Total |
Total |
Before
|
2x4 =
8 u |
1x4 =
4 u |
3x4 =
12 u |
4x3 =
12 u |
Change
|
- 0.4x4 =
- 1.6 u |
- 111 |
|
- 3x3 =
- 9 u |
After
|
1.6x4 =
6.4 u |
4 u - 111 |
|
1x3 =
3 u |
The total number of stamps that Lucy had at first is repeated. Make the total number of stamps at first the same. LCM 3 and 4 is 12.
Number of blue stamps that Lucy gave away
= 20% x 2 u
=
20100 x 2 u
= 0.4 u
1.6 u - 111 = 9 u
9 u - 1.6 u = 111
7.4 u = 111
1 u = 111 ÷ 7.4 = 15
Number of stamps that Lucy gave away
= 9 u
= 9 x 15
= 135
Answer(s): 135
