There were a total of thirty-six 10-cent coins and 50-cent coins in a bag. Given that the total amount of money in the bag was $15.20. 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 |
36
|
36 x 50 = 1800¢ |
0
|
0
|
1800¢
|
35
|
35 x 50 = 1750¢ |
1
|
1 x 10 = 10¢ |
1760¢
|
29
|
29 x 50 = 1450¢ |
7
|
7 x 10 = 70¢ |
1520¢ |
$1 = 100¢
$15.20 = 1520¢
Amount in the bag if all are 50-cent coins
= 36 x 50
= 1800¢
Big difference between the value of 50-cent coins and 10-cent coins
= 1800 - 1520
= 280¢
Small difference between the value of one 50-cent coin and one 10-cent coin
= 50 - 10
= 40¢
Number of 10-cent coins
= 280 ÷ 40
= 7
Answer(s): 7