There were a total of fifty 10-cent coins and 50-cent coins in a bag. Given that the total amount of money in the bag was $21.40. How many 10-cent coins were there in the bag?
Number of
50-cent coins |
Value of
50-cent coins |
Number of
10-cent coins |
Value of
10-cent coins |
Total
value |
50
|
50 x 50
= 2500¢ |
0
|
0
|
2500¢
|
49
|
49 x 50
= 2450¢ |
1
|
1 x 10
= 10¢ |
2460¢
|
41
|
41 x 50
= 2050¢ |
9
|
9 x 10
= 90¢ |
2140¢ |
$1 = 100¢
$21.40 = 2140¢
Amount in the bag if all are 50-cent coins
= 50 x 50
= 2500¢
Big difference between the value of 50-cent coins and 10-cent coins
= 2500 - 2140
= 360¢
Small difference between the value of one 50-cent coin and one 10-cent coin
= 50 - 10
= 40¢
Number of 10-cent coins
= 360 ÷ 40
= 9
Answer(s): 9
