Gem had some marble collection.
12 of them were gold and the rest were red. She gave away 168 of the red marbles and 30% of the gold marbles. She then had
14 of her marble collection left. How many marbles did Gem give away?
| |
Gold |
Red |
Total |
Total |
Before
|
1x2 =
2 u |
1x2 =
2 u |
2x2 =
4 u |
4x1 =
4 u |
Change
|
- 0.3x2 =
- 0.6 u |
- 168 |
|
- 3x1 =
- 3 u |
After
|
0.7x2 =
1.4 u |
2 u - 168 |
|
1x1 =
1 u |
The total number of marbles that Gem had at first is repeated. Make the total number of marbles at first the same. LCM 2 and 4 is 4.
Number of gold marbles that Gem gave away
= 30% x 1 u
=
30100 x 1 u
= 0.3 u
0.6 u - 168 = 3 u
3 u - 0.6 u = 168
2.4 u = 168
1 u = 168 ÷ 2.4 = 70
Number of marbles that Gem gave away
= 3 u
= 3 x 70
= 210
Answer(s): 210
