Will has 3 more 50-cent coins than 20-cent coins. After he used 14 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 + 3 |
1 u |
Change |
- 14 |
|
After |
1 u - 11 |
1 u |
|
50¢ |
20¢ |
Number |
1 u - 11 |
1 u |
Value |
50 |
20 |
Total value |
50 u - 550 |
20 u |
$1 = 100¢
$1.40 = 140¢
Number of 50¢ coins in the end
= 1 u + 3 - 14
= 1 u - 11
Total value of 50¢ coins in the end
= 50 x (1 u - 11)
= 50 u - 550
Total value of 20¢ coins in the end
= 20 x 1 u
= 20 u
After using 14 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 - 550 = 20 u + 140
50 u - 20 u = 140 + 550
30 u = 690
1 u = 690 ÷ 30 = 23
Number of coins that Will had in the end
= 1 u + 1 u - 11
= 2 u - 11
= (2 x 23) - 11
= 46 - 11
= 35
Answer(s): 35