Winnie had some marble collection.
13 of them were grey and the rest were brown. She gave away 117 of the brown marbles and 30% of the grey marbles. She then had
14 of her marble collection left. How many marbles did Winnie give away?
| |
Grey |
Brown |
Total |
Total |
Before
|
1x4 =
4 u |
2x4 =
8 u |
3x4 =
12 u |
4x3 =
12 u |
Change
|
- 0.3x4 =
- 1.2 u |
- 117 |
|
- 3x3 =
- 9 u |
After
|
0.7x4 =
2.8 u |
8 u - 117 |
|
1x3 =
3 u |
The total number of marbles that Winnie had at first is repeated. Make the total number of marbles at first the same. LCM 3 and 4 is 12.
Number of grey marbles that Winnie gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
1.2 u - 117 = 9 u
9 u - 1.2 u = 117
7.8 u = 117
1 u = 117 ÷ 7.8 = 15
Number of marbles that Winnie gave away
= 9 u
= 9 x 15
= 135
Answer(s): 135
