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 $4.40. 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¢
|
12
|
12 x 20
= 240¢ |
20
|
20 x 10
= 200¢ |
440¢ |
$1 = 100¢
$4.40 = 440¢
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 - 440
= 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
