Nora had some button collection.
12 of them were purple and the rest were green. She gave away 170 of the green buttons and 20% of the purple buttons. She then had
13 of her button collection left. How many buttons did Nora give away?
| |
Purple |
Green |
Total |
Total |
Before
|
1x3 =
3 u |
1x3 =
3 u |
2x3 =
6 u |
3x2 =
6 u |
Change
|
- 0.2x3 =
- 0.6 u |
- 170 |
|
- 2x2 =
- 4 u |
After
|
0.8x3 =
2.4 u |
3 u - 170 |
|
1x2 =
2 u |
The total number of buttons that Nora had at first is repeated. Make the total number of buttons at first the same. LCM 2 and 3 is 6.
Number of purple buttons that Nora gave away
= 20% x 1 u
=
20100 x 1 u
= 0.2 u
0.6 u - 170 = 4 u
4 u - 0.6 u = 170
3.4 u = 170
1 u = 170 ÷ 3.4 = 50
Number of buttons that Nora gave away
= 4 u
= 4 x 50
= 200
Answer(s): 200
