Kylie had some button collection.
12 of them were black and the rest were yellow. She gave away 164 of the yellow buttons and 30% of the black buttons. She then had
16 of her button collection left. How many buttons did Kylie give away?
| |
Black |
Yellow |
Total |
Total |
Before
|
1x3 =
3 u |
1x3 =
3 u |
2x3 =
6 u |
6x1 =
6 u |
Change
|
- 0.3x3 =
- 0.9 u |
- 164 |
|
- 5x1 =
- 5 u |
After
|
0.7x3 =
2.1 u |
3 u - 164 |
|
1x1 =
1 u |
The total number of buttons that Kylie had at first is repeated. Make the total number of buttons at first the same. LCM 2 and 6 is 6.
Number of black buttons that Kylie gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
0.9 u - 164 = 5 u
5 u - 0.9 u = 164
4.1 u = 164
1 u = 164 ÷ 4.1 = 40
Number of buttons that Kylie gave away
= 5 u
= 5 x 40
= 200
Answer(s): 200
