There were a total of thirty-six 10-cent coins and 20-cent coins in a bag. Given that the total amount of money in the bag was $5.20. 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 |
36
|
36 x 20 = 720¢ |
0
|
0
|
720¢
|
35
|
35 x 20 = 700¢ |
1
|
1 x 10 = 10¢ |
710¢
|
16
|
16 x 20 = 320¢ |
20
|
20 x 10 = 200¢ |
520¢ |
$1 = 100¢
$5.20 = 520¢
Amount in the bag if all are 20-cent coins
= 36 x 20
= 720¢
Big difference between the value of 20-cent coins and 10-cent coins
= 720 - 520
= 200¢
Small difference between the value of one 20-cent coin and one 10-cent coin
= 20 - 10
= 10¢
Number of 10-cent coins
= 200 ÷ 10
= 20
Answer(s): 20