The ratio of the number of red coins to blue coins is 7 : 2. After Daniel gives away 20 red coins and buys another 60 blue coins, there is equal number of red coins and blue coins. How many coins does Daniel have now?
| |
Red |
Blue |
| Before |
7 u |
2 u |
| Change |
- 20 |
+ 60 |
| After |
7 u - 20 |
2 u + 60 |
The number of red coins and blue coins in the end is the same.
7 u - 20 = 2 u + 60
7 u - 2 u = 60 + 20
5 u = 80
1 u = 80 ÷ 5 = 16
Number of coins that Daniel has now
= 7 u - 20 + 2 u + 60
= 7 u + 2 u - 20 + 60
= 9 u + 40
= 9 x 16 + 40
= 144 + 40
= 184
Answer(s): 184
