There are some purple and gold marbles in a container. If 10 purple marbles are removed from the container, the total number of marbles left will be 7 times the number of purple marbles left. If 6 gold marbles are removed from the container, the total number of marbles left will be 4 times the number of purple marbles. How many marbles are there in the container?
|
Case 1 |
Case 2 |
|
Purple marbles |
Gold marbles |
Purple marbles |
Gold marbles |
Before |
1 u + 10 |
6 u |
1 p |
3 p + 6 |
Change |
- 10 |
|
|
- 6 |
After |
1 u |
6 u |
1 p |
3 p |
Number of gold marbles in the end for Case 1
= 7 u - 1 u
= 6 u
Number of purple marbles in the end for Case 2
= 4 p - 1 p
= 3 p
The number of purple marbles at first is the same for Case 1 and Case 2.
The number of gold marbles at first is also the same for Case 1 and Case 2.
1 u + 10 = 1 p --- (1)
6 u = 3 p + 6
6 u - 6 =
3 p --- (2)
Make p the same.
(1)
x3 3 u + 30 =
3 p --- (3)
(2) = (3)
6 u - 6 = 3 u + 30
6 u - 3 u = 30 + 6
3 u = 36
1 u = 36 ÷ 3 = 12
Number of marbles in the container
= (1 u + 10) + 6 u
= 7 u + 10
= (7 x 12) + 10
= 84 + 10
= 94
Answer(s): 94