Reggie has 2 more 20-cent coins than 10-cent coins. After he used 8 of his 20-cent coins, the total value of 20-cent coins is $3.40 more than the total value of 10-cent coins. How many coins did he have at first?
| |
20¢ |
10¢ |
| Before |
1 u + 2 |
1 u |
| Change |
- 8 |
|
| After |
1 u - 6 |
1 u |
| |
20¢ |
10¢ |
| Number |
1 u - 6 |
1 u |
| Value |
20 |
10 |
| Total value |
20 u - 120 |
10 u |
$1 = 100¢
$3.40 = 340¢
Number of 20¢ coins in the end
= 1 u + 2 - 8
= 1 u - 6
Total value of 20¢ coins in the end
= 20 x (1 u - 6)
= 20 u - 120
Total value of 10¢ coins in the end
= 10 x 1 u
= 10 u
After using 8 20-cent coins, the value of 20-cent coins is 340¢ more than the value of 10-cent coins. If another 340¢ is added to the 10-cent coins, the total value of 20-cent coins and 10-cent coins will be the same.
20 u - 120 = 10 u + 340
20 u - 10 u = 340 + 120
10 u = 460
1 u = 460 ÷ 10 = 46
Number of coins that Reggie had at first
= 1 u + 1 u + 2
= 2 u + 2
= (2 x 46) + 2
= 92 + 2
= 94
Answer(s): 94
