Asher has 9 more 10-cent coins than 5-cent coins. After he used 15 of his 10-cent coins, the total value of 10-cent coins is $3.90 more than the total value of 5-cent coins. How many coins did he have in the end?
|
10¢ |
5¢ |
Before |
1 u + 9 |
1 u |
Change |
- 15 |
|
After |
1 u - 6 |
1 u |
|
10¢ |
5¢ |
Number |
1 u - 6 |
1 u |
Value |
10 |
5 |
Total value |
10 u - 60 |
5 u |
$1 = 100¢
$3.90 = 390¢
Number of 10¢ coins in the end
= 1 u + 9 - 15
= 1 u - 6
Total value of 10¢ coins in the end
= 10 x (1 u - 6)
= 10 u - 60
Total value of 5¢ coins in the end
= 5 x 1 u
= 5 u
After using 15 10-cent coins, the value of 10-cent coins is 390¢ more than the value of 5-cent coins. If another 390¢ is added to the 5-cent coins, the total value of 10-cent coins and 5-cent coins will be the same.
10 u - 60 = 5 u + 390
10 u - 5 u = 390 + 60
5 u = 450
1 u = 450 ÷ 5 = 90
Number of coins that Asher had in the end
= 1 u + 1 u - 6
= 2 u - 6
= (2 x 90) - 6
= 180 - 6
= 174
Answer(s): 174