There are some purple and red beads in a container. If 8 purple beads are removed from the container, the total number of beads left will be 8 times the number of purple beads left. If 39 red beads are removed from the container, the total number of beads left will be 3 times the number of purple beads. How many beads are there in the container?
|
Case 1 |
Case 2 |
|
Purple beads |
Red beads |
Purple beads |
Red beads |
Before |
1 u + 8 |
7 u |
1 p |
2 p + 39 |
Change |
- 8 |
|
|
- 39 |
After |
1 u |
7 u |
1 p |
2 p |
Number of red beads in the end for Case 1
= 8 u - 1 u
= 7 u
Number of purple beads in the end for Case 2
= 3 p - 1 p
= 2 p
The number of purple beads at first is the same for Case 1 and Case 2.
The number of red beads at first is also the same for Case 1 and Case 2.
1 u + 8 = 1 p --- (1)
7 u = 2 p + 39
7 u - 39 =
2 p --- (2)
Make p the same.
(1)
x2 2 u + 16 =
2 p --- (3)
(2) = (3)
7 u - 39 = 2 u + 16
7 u - 2 u = 16 + 39
5 u = 55
1 u = 55 ÷ 5 = 11
Number of beads in the container
= (1 u + 8) + 7 u
= 8 u + 8
= (8 x 11) + 8
= 88 + 8
= 96
Answer(s): 96