Fiona had some stamp collection.
13 of them were white and the rest were green. She gave away 136 of the green stamps and 20% of the white stamps. She then had
27 of her stamp collection left. How many stamps did Fiona give away?
| |
White |
Green |
Total |
Total |
Before
|
1x7 =
7 u |
2x7 =
14 u |
3x7 =
21 u |
7x3 =
21 u |
Change
|
- 0.2x7 =
- 1.4 u |
- 136 |
|
- 5x3 =
- 15 u |
After
|
0.8x7 =
5.6 u |
14 u - 136 |
|
2x3 =
6 u |
The total number of stamps that Fiona had at first is repeated. Make the total number of stamps at first the same. LCM 3 and 7 is 21.
Number of white stamps that Fiona gave away
= 20% x 1 u
=
20100 x 1 u
= 0.2 u
1.4 u - 136 = 15 u
15 u - 1.4 u = 136
13.6 u = 136
1 u = 136 ÷ 13.6 = 10
Number of stamps that Fiona gave away
= 15 u
= 15 x 10
= 150
Answer(s): 150
