The ratio of the number of blue coins to green coins is 3 : 1. After Ryan gives away 30 blue coins and buys another 60 green coins, there is equal number of blue coins and green coins. How many coins does Ryan have now?
| |
Blue |
Green |
| Before |
3 u |
1 u |
| Change |
- 30 |
+ 60 |
| After |
3 u - 30 |
1 u + 60 |
The number of blue coins and green coins in the end is the same.
3 u - 30 = 1 u + 60
3 u - 1 u = 60 + 30
2 u = 90
1 u = 90 ÷ 2 = 45
Number of coins that Ryan has now
= 3 u - 30 + 1 u + 60
= 3 u + 1 u - 30 + 60
= 4 u + 30
= 4 x 45 + 30
= 180 + 30
= 210
Answer(s): 210
