There were a total of thirty-two 10-cent coins and 20-cent coins in a bag. Given that the total amount of money in the bag was $5.40. How many 10-cent coins were there in the bag?
Number of 20-cent coins |
Value of 20-cent coins |
Number of 10-cent coins |
Value of 10-cent coins |
Total value |
32
|
32 x 20 = 640¢ |
0
|
0
|
640¢
|
31
|
31 x 20 = 620¢ |
1
|
1 x 10 = 10¢ |
630¢
|
22
|
22 x 20 = 440¢ |
10
|
10 x 10 = 100¢ |
540¢ |
$1 = 100¢
$5.40 = 540¢
Amount in the bag if all are 20-cent coins
= 32 x 20
= 640¢
Big difference between the value of 20-cent coins and 10-cent coins
= 640 - 540
= 100¢
Small difference between the value of one 20-cent coin and one 10-cent coin
= 20 - 10
= 10¢
Number of 10-cent coins
= 100 ÷ 10
= 10
Answer(s): 10