There are some pink and silver marbles in a box. If 2 pink marbles are removed from the box, the total number of marbles left will be 8 times the number of pink marbles left. If 34 silver marbles are removed from the box, the total number of marbles left will be 4 times the number of pink marbles. How many marbles are there in the box?
|
Case 1 |
Case 2 |
|
Pink marbles |
Silver marbles |
Pink marbles |
Silver marbles |
Before |
1 u + 2 |
7 u |
1 p |
3 p + 34 |
Change |
- 2 |
|
|
- 34 |
After |
1 u |
7 u |
1 p |
3 p |
Number of silver marbles in the end for Case 1
= 8 u - 1 u
= 7 u
Number of pink marbles in the end for Case 2
= 4 p - 1 p
= 3 p
The number of pink marbles at first is the same for Case 1 and Case 2.
The number of silver marbles at first is also the same for Case 1 and Case 2.
1 u + 2 = 1 p --- (1)
7 u = 3 p + 34
7 u - 34 =
3 p --- (2)
Make p the same.
(1)
x3 3 u + 6 =
3 p --- (3)
(2) = (3)
7 u - 34 = 3 u + 6
7 u - 3 u = 6 + 34
4 u = 40
1 u = 40 ÷ 4 = 10
Number of marbles in the box
= (1 u + 2) + 7 u
= 8 u + 2
= (8 x 10) + 2
= 80 + 2
= 82
Answer(s): 82