There are 25% more gold beads than black beads in a bag. After Vincent removed 20% of the gold beads and increased the number of black beads by 10%, there are now 32 fewer gold beads than black beads. Find the number of black beads at first.
|
Gold |
Black |
Before |
5 u |
4 u |
Change |
- 1 u |
+ 0.4 u |
After |
4 u |
4.4 u |
Number of gold beads in percentage
= 100% + 25%
= 125%
125% =
125100 =
54Number of gold beads that Vincent removed
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of black beads that Vincent increased
= 10% x 4 u
=
10100 x 4 u
= 0.4 u
Number of gold beads in the end
= 5 u - 1 u
= 4 u
Number of black beads in the end
= 4 u + 0.4 u
= 4.4 u
Number of fewer gold beads than black beads in the end
= 4.4 u - 4 u
= 0.4 u
0.4 u = 32
1 u = 32 ÷ 0.4 = 80
Number of black beads at first
= 4 u
= 4 x 80
= 320
Answer(s): 320