Neave has 8 more 10-cent coins than 5-cent coins. After he used 19 of his 10-cent coins, the total value of 10-cent coins is $1.40 more than the total value of 5-cent coins. How many coins did he have in the end?
|
10¢ |
5¢ |
Before |
1 u + 8 |
1 u |
Change |
- 19 |
|
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¢
$1.40 = 140¢
Number of 10¢ coins in the end
= 1 u + 8 - 19
= 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 19 10-cent coins, the value of 10-cent coins is 140¢ more than the value of 5-cent coins. If another 140¢ 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 + 140
10 u - 5 u = 140 + 110
5 u = 250
1 u = 250 ÷ 5 = 50
Number of coins that Neave had in the end
= 1 u + 1 u - 11
= 2 u - 11
= (2 x 50) - 11
= 100 - 11
= 89
Answer(s): 89