There are some grey and green beads in a box. If 3 grey beads are removed from the box, the total number of beads left will be 8 times the number of grey beads left. If 54 green beads are removed from the box, the total number of beads left will be 3 times the number of grey beads. How many beads are there in the box?
|
Case 1 |
Case 2 |
|
Grey beads |
Green beads |
Grey beads |
Green beads |
Before |
1 u + 3 |
7 u |
1 p |
2 p + 54 |
Change |
- 3 |
|
|
- 54 |
After |
1 u |
7 u |
1 p |
2 p |
Number of green beads in the end for Case 1
= 8 u - 1 u
= 7 u
Number of grey beads in the end for Case 2
= 3 p - 1 p
= 2 p
The number of grey beads at first is the same for Case 1 and Case 2.
The number of green beads at first is also the same for Case 1 and Case 2.
1 u + 3 = 1 p --- (1)
7 u = 2 p + 54
7 u - 54 =
2 p --- (2)
Make p the same.
(1)
x2 2 u + 6 =
2 p --- (3)
(2) = (3)
7 u - 54 = 2 u + 6
7 u - 2 u = 6 + 54
5 u = 60
1 u = 60 ÷ 5 = 12
Number of beads in the box
= (1 u + 3) + 7 u
= 8 u + 3
= (8 x 12) + 3
= 96 + 3
= 99
Answer(s): 99