Tim has a total of 16 fifty-cent and ten-cent coins. The total value of the coins is $4. If he spends all the fifty-cent coins on a marker, how much does the marker cost?
Number of
fifty-cent coins |
Value of
fifty-cent coins |
Number of
ten-cent coins |
Value of
ten-cent coins |
Total
value |
| 16 |
16 x 50
= 800¢ |
0 |
0 |
800¢ |
| 15 |
15 x 50
= 750¢ |
1 |
1 x 10
= 10¢ |
760¢ |
| 6 |
6 x 50
= 300¢ |
10 |
10 x 10
= 100¢ |
400¢ |
$1 = 100¢
$4 = 400¢
Total value if all the coins are fifty-cent coins
= 16 x 50
= 800¢
Big difference between the value of fifty-cent coins and ten-cent coins
= 800 - 400
= 400¢
Small difference between the value of one fifty-cent coin and one ten-cent coin
= 50 - 10
= 40¢
Number of ten-cent coins
= 400 ÷ 40
= 10
Number of fifty-cent coins
= 16 - 10
= 6
Cost of the marker
= 6 x 50
= 300¢
= $3
Answer(s): $3
