Warren has 7 more 50-cent coins than 5-cent coins. After he used 18 of his 50-cent coins, the total value of 50-cent coins is $4.40 more than the total value of 5-cent coins. How many coins did he have at first?
| |
50¢ |
5¢ |
| Before |
1 u + 7 |
1 u |
| Change |
- 18 |
|
| After |
1 u - 11 |
1 u |
| |
50¢ |
5¢ |
| Number |
1 u - 11 |
1 u |
| Value |
50 |
5 |
| Total value |
50 u - 550 |
5 u |
$1 = 100¢
$4.40 = 440¢
Number of 50¢ coins in the end
= 1 u + 7 - 18
= 1 u - 11
Total value of 50¢ coins in the end
= 50 x (1 u - 11)
= 50 u - 550
Total value of 5¢ coins in the end
= 5 x 1 u
= 5 u
After using 18 50-cent coins, the value of 50-cent coins is 440¢ more than the value of 5-cent coins. If another 440¢ is added to the 5-cent coins, the total value of 50-cent coins and 5-cent coins will be the same.
50 u - 550 = 5 u + 440
50 u - 5 u = 440 + 550
45 u = 990
1 u = 990 ÷ 45 = 22
Number of coins that Warren had at first
= 1 u + 1 u + 7
= 2 u + 7
= (2 x 22) + 7
= 44 + 7
= 51
Answer(s): 51
