There are some black and silver beads in a container. If 8 black beads are removed from the container, the total number of beads left will be 9 times the number of black beads left. If 56 silver beads are removed from the container, the total number of beads left will be 3 times the number of black beads. How many beads are there in the container?
|
Case 1 |
Case 2 |
|
Black beads |
Silver beads |
Black beads |
Silver beads |
Before |
1 u + 8 |
8 u |
1 p |
2 p + 56 |
Change |
- 8 |
|
|
- 56 |
After |
1 u |
8 u |
1 p |
2 p |
Number of silver beads in the end for Case 1
= 9 u - 1 u
= 8 u
Number of black beads in the end for Case 2
= 3 p - 1 p
= 2 p
The number of black beads at first is the same for Case 1 and Case 2.
The number of silver beads at first is also the same for Case 1 and Case 2.
1 u + 8 = 1 p --- (1)
8 u = 2 p + 56
8 u - 56 =
2 p --- (2)
Make p the same.
(1)
x2 2 u + 16 =
2 p --- (3)
(2) = (3)
8 u - 56 = 2 u + 16
8 u - 2 u = 16 + 56
6 u = 72
1 u = 72 ÷ 6 = 12
Number of beads in the container
= (1 u + 8) + 8 u
= 9 u + 8
= (9 x 12) + 8
= 108 + 8
= 116
Answer(s): 116