Dylan has 5 more 10-cent coins than 5-cent coins. After he used 16 of his 10-cent coins, the total value of 10-cent coins is $3.30 more than the total value of 5-cent coins. How many coins did he have in the end?
| |
10¢ |
5¢ |
| Before |
1 u + 5 |
1 u |
| Change |
- 16 |
|
| After |
1 u - 11 |
1 u |
| |
10¢ |
5¢ |
| Number |
1 u - 11 |
1 u |
| Value |
10 |
5 |
| Total value |
10 u - 110 |
5 u |
$1 = 100¢
$3.30 = 330¢
Number of 10¢ coins in the end
= 1 u + 5 - 16
= 1 u - 11
Total value of 10¢ coins in the end
= 10 x (1 u - 11)
= 10 u - 110
Total value of 5¢ coins in the end
= 5 x 1 u
= 5 u
After using 16 10-cent coins, the value of 10-cent coins is 330¢ more than the value of 5-cent coins. If another 330¢ is added to the 5-cent coins, the total value of 10-cent coins and 5-cent coins will be the same.
10 u - 110 = 5 u + 330
10 u - 5 u = 330 + 110
5 u = 440
1 u = 440 ÷ 5 = 88
Number of coins that Dylan had in the end
= 1 u + 1 u - 11
= 2 u - 11
= (2 x 88) - 11
= 176 - 11
= 165
Answer(s): 165
