Asher has 9 more 50-cent coins than 20-cent coins. After he used 17 of his 50-cent coins, the total value of 50-cent coins is $1.40 more than the total value of 20-cent coins. How many coins did he have in the end?
| |
50¢ |
20¢ |
| Before |
1 u + 9 |
1 u |
| Change |
- 17 |
|
| After |
1 u - 8 |
1 u |
| |
50¢ |
20¢ |
| Number |
1 u - 8 |
1 u |
| Value |
50 |
20 |
| Total value |
50 u - 400 |
20 u |
$1 = 100¢
$1.40 = 140¢
Number of 50¢ coins in the end
= 1 u + 9 - 17
= 1 u - 8
Total value of 50¢ coins in the end
= 50 x (1 u - 8)
= 50 u - 400
Total value of 20¢ coins in the end
= 20 x 1 u
= 20 u
After using 17 50-cent coins, the value of 50-cent coins is 140¢ more than the value of 20-cent coins. If another 140¢ is added to the 20-cent coins, the total value of 50-cent coins and 20-cent coins will be the same.
50 u - 400 = 20 u + 140
50 u - 20 u = 140 + 400
30 u = 540
1 u = 540 ÷ 30 = 18
Number of coins that Asher had in the end
= 1 u + 1 u - 8
= 2 u - 8
= (2 x 18) - 8
= 36 - 8
= 28
Answer(s): 28
