There are some pink and gold marbles in a box. If 2 pink marbles are removed from the box, the total number of marbles left will be 9 times the number of pink marbles left. If 8 gold marbles are removed from the box, the total number of marbles left will be 6 times the number of pink marbles. How many marbles are there in the box?
|
Case 1 |
Case 2 |
|
Pink marbles |
Gold marbles |
Pink marbles |
Gold marbles |
Before |
1 u + 2 |
8 u |
1 p |
5 p + 8 |
Change |
- 2 |
|
|
- 8 |
After |
1 u |
8 u |
1 p |
5 p |
Number of gold marbles in the end for Case 1
= 9 u - 1 u
= 8 u
Number of pink marbles in the end for Case 2
= 6 p - 1 p
= 5 p
The number of pink 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 + 2 = 1 p --- (1)
8 u = 5 p + 8
8 u - 8 =
5 p --- (2)
Make p the same.
(1)
x5 5 u + 10 =
5 p --- (3)
(2) = (3)
8 u - 8 = 5 u + 10
8 u - 5 u = 10 + 8
3 u = 18
1 u = 18 ÷ 3 = 6
Number of marbles in the box
= (1 u + 2) + 8 u
= 9 u + 2
= (9 x 6) + 2
= 54 + 2
= 56
Answer(s): 56