The ratio of the number of red beads to green beads is 7 : 5. After Howard gives away 30 red beads and buys another 50 green beads, there is equal number of red beads and green beads. How many beads does Howard have now?
| |
Red |
Green |
| Before |
7 u |
5 u |
| Change |
- 30 |
+ 50 |
| After |
7 u - 30 |
5 u + 50 |
The number of red beads and green beads in the end is the same.
7 u - 30 = 5 u + 50
7 u - 5 u = 50 + 30
2 u = 80
1 u = 80 ÷ 2 = 40
Number of beads that Howard has now
= 7 u - 30 + 5 u + 50
= 7 u + 5 u - 30 + 50
= 12 u + 20
= 12 x 40 + 20
= 480 + 20
= 500
Answer(s): 500
