Julie saved two coins every day from Monday to Sunday by putting them into a coin box. Each coin was either a 5¢ or 50¢ coin. The total value of the coins at the end of 6 weeks was $14.10. How many of the coins were 50¢ coins?
| 50¢ |
Value of 50¢ |
5¢ |
Value of 5¢ |
Total value |
84
|
84 x 50¢ =
4200¢ |
0 |
0 x 5¢ =
0 |
4200¢ |
83
|
83 x 50¢ =
4150¢ |
1 |
1 x 5¢ =
5¢ |
4155¢ |
22
|
22 x 50¢ =
1100¢ |
62
|
62 x 5¢ =
310¢ |
1410¢ |
$1 = 100¢
$14.10 = 1410¢
Number of coins in one week
= 2 x 7
= 14
Number of coins in 6 weeks
= 6 x 14
= 84
Total amount saved if all the coins were 50¢
= 84 x 50
= 4200¢
Big difference between the total values of 50¢ coins and 5¢ coins
= 4200 - 1410
= 2790¢
Small difference between the value of one 50¢ coin and one 5¢ coin
= 50 - 5
= 45¢
Number of 5¢ coins
= 2790 ÷ 45
= 62
Number of 50¢ coins
= 84 - 62
= 22
Answer(s): 22
