Anna had some marble collection.
12 of them were green and the rest were yellow. She gave away 180 of the yellow marbles and 10% of the green marbles. She then had
15 of her marble collection left. How many marbles did Anna give away?
| |
Green |
Yellow |
Total |
Total |
Before
|
1x5 =
5 u |
1x5 =
5 u |
2x5 =
10 u |
5x2 =
10 u |
Change
|
- 0.1x5 =
- 0.5 u |
- 180 |
|
- 4x2 =
- 8 u |
After
|
0.9x5 =
4.5 u |
5 u - 180 |
|
1x2 =
2 u |
The total number of marbles that Anna had at first is repeated. Make the total number of marbles at first the same. LCM 2 and 5 is 10.
Number of green marbles that Anna gave away
= 10% x 1 u
=
10100 x 1 u
= 0.1 u
0.5 u - 180 = 8 u
8 u - 0.5 u = 180
7.5 u = 180
1 u = 180 ÷ 7.5 = 24
Number of marbles that Anna gave away
= 8 u
= 8 x 24
= 192
Answer(s): 192
