Julie had some stamp collection.
12 of them were purple and the rest were white. She gave away 111 of the white stamps and 10% of the purple stamps. She then had
13 of her stamp collection left. How many stamps did Julie give away?
| |
Purple |
White |
Total |
Total |
Before
|
1x3 =
3 u |
1x3 =
3 u |
2x3 =
6 u |
3x2 =
6 u |
Change
|
- 0.1x3 =
- 0.3 u |
- 111 |
|
- 2x2 =
- 4 u |
After
|
0.9x3 =
2.7 u |
3 u - 111 |
|
1x2 =
2 u |
The total number of stamps that Julie had at first is repeated. Make the total number of stamps at first the same. LCM 2 and 3 is 6.
Number of purple stamps that Julie gave away
= 10% x 1 u
=
10100 x 1 u
= 0.1 u
0.3 u - 111 = 4 u
4 u - 0.3 u = 111
3.7 u = 111
1 u = 111 ÷ 3.7 = 30
Number of stamps that Julie gave away
= 4 u
= 4 x 30
= 120
Answer(s): 120
