Tiffany had some stamp collection.
45 of them were purple and the rest were silver. She gave away 159 of the silver stamps and 10% of the purple stamps. She then had
18 of her stamp collection left. How many stamps did Tiffany give away?
| |
Purple |
Silver |
Total |
Total |
Before
|
4x8 =
32 u |
1x8 =
8 u |
5x8 =
40 u |
8x5 =
40 u |
Change
|
- 0.4x8 =
- 3.2 u |
- 159 |
|
- 7x5 =
- 35 u |
After
|
3.6x8 =
28.8 u |
8 u - 159 |
|
1x5 =
5 u |
The total number of stamps that Tiffany had at first is repeated. Make the total number of stamps at first the same. LCM 5 and 8 is 40.
Number of purple stamps that Tiffany gave away
= 10% x 4 u
=
10100 x 4 u
= 0.4 u
3.2 u - 159 = 35 u
35 u - 3.2 u = 159
31.8 u = 159
1 u = 159 ÷ 31.8 = 5
Number of stamps that Tiffany gave away
= 35 u
= 35 x 5
= 175
Answer(s): 175
