There are some green and silver beads in a container. If 5 green beads are removed from the container, the total number of beads left will be 9 times the number of green beads left. If 20 silver beads are removed from the container, the total number of beads left will be 4 times the number of green beads. How many beads are there in the container?
|
Case 1 |
Case 2 |
|
Green beads |
Silver beads |
Green beads |
Silver beads |
Before |
1 u + 5 |
8 u |
1 p |
3 p + 20 |
Change |
- 5 |
|
|
- 20 |
After |
1 u |
8 u |
1 p |
3 p |
Number of silver beads in the end for Case 1
= 9 u - 1 u
= 8 u
Number of green beads in the end for Case 2
= 4 p - 1 p
= 3 p
The number of green 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 + 5 = 1 p --- (1)
8 u = 3 p + 20
8 u - 20 =
3 p --- (2)
Make p the same.
(1)
x3 3 u + 15 =
3 p --- (3)
(2) = (3)
8 u - 20 = 3 u + 15
8 u - 3 u = 15 + 20
5 u = 35
1 u = 35 ÷ 5 = 7
Number of beads in the container
= (1 u + 5) + 8 u
= 9 u + 5
= (9 x 7) + 5
= 63 + 5
= 68
Answer(s): 68