Owen has 10-cent coins and 50-cent coins. The total value of all his coins is $12. He has 6 less 10-cent coins than 50-cent coins. How many coins does he have altogether?
|
10-cent |
50-cent |
Total |
Number |
1 u |
1 u + 6 |
2 u + 6 |
Value |
10 |
50 |
|
Total value |
10 u |
50 u + 300 |
60 u + 300 |
$1 = 100¢
$12 = 12 x 100 = 1200¢
Owen has 6 more 50-cent coins than 10-cent coins.
Number of 10-cent coins = 1 u
Number of 50-cent coins = 1 u + 6
Total value of 10-cent coins
= 10 x 1 u
= 10 u
Total value of 50-cent coins
= 50 x (1 u + 6)
= 50 u + 300
Total value of the coins
= 10 u + 50 u + 300
= 60 u + 300
60 u + 300 = 1200
60 u = 1200 - 300
60 u = 900
1 u = 900 ÷ 60 = 15
Total number of coins
= 1 u + (1 u + 6)
= 2 u + 6
= 2 x 15 + 6
= 30 + 6
= 36
Answer(s): 36