The ratio of the number of green beads to red beads is 5 : 2. After Andy gives away 30 green beads and buys another 60 red beads, there is equal number of green beads and red beads. How many beads does Andy have now?
| |
Green |
Red |
| Before |
5 u |
2 u |
| Change |
- 30 |
+ 60 |
| After |
5 u - 30 |
2 u + 60 |
The number of green beads and red beads in the end is the same.
5 u - 30 = 2 u + 60
5 u - 2 u = 60 + 30
3 u = 90
1 u = 90 ÷ 3 = 30
Number of beads that Andy has now
= 5 u - 30 + 2 u + 60
= 5 u + 2 u - 30 + 60
= 7 u + 30
= 7 x 30 + 30
= 210 + 30
= 240
Answer(s): 240
