Rachel had some stamp collection.
35 of them were gold and the rest were green. She gave away 164 of the green stamps and 20% of the gold stamps. She then had
13 of her stamp collection left. How many stamps did Rachel give away?
| |
Gold |
Green |
Total |
Total |
Before
|
3x3 =
9 u |
2x3 =
6 u |
5x3 =
15 u |
3x5 =
15 u |
Change
|
- 0.6x3 =
- 1.8 u |
- 164 |
|
- 2x5 =
- 10 u |
After
|
2.4x3 =
7.2 u |
6 u - 164 |
|
1x5 =
5 u |
The total number of stamps that Rachel had at first is repeated. Make the total number of stamps at first the same. LCM 5 and 3 is 15.
Number of gold stamps that Rachel gave away
= 20% x 3 u
=
20100 x 3 u
= 0.6 u
1.8 u - 164 = 10 u
10 u - 1.8 u = 164
8.2 u = 164
1 u = 164 ÷ 8.2 = 20
Number of stamps that Rachel gave away
= 10 u
= 10 x 20
= 200
Answer(s): 200
