Jeremy has 5-cent coins and 10-cent coins. The total value of all his coins is $33. He has 6 less 5-cent coins than 10-cent coins. How many coins does he have altogether?
| |
5-cent |
10-cent |
Total |
| Number |
1 u |
1 u + 6 |
2 u + 6 |
| Value |
5 |
10 |
|
| Total value |
5 u |
10 u + 60 |
15 u + 60 |
$1 = 100¢
$33 = 33 x 100 = 3300¢
Jeremy has 6 more 10-cent coins than 5-cent coins.
Number of 5-cent coins = 1 u
Number of 10-cent coins = 1 u + 6
Total value of 5-cent coins
= 5 x 1 u
= 5 u
Total value of 10-cent coins
= 10 x (1 u + 6)
= 10 u + 60
Total value of the coins
= 5 u + 10 u + 60
= 15 u + 60
15 u + 60 = 3300
15 u = 3300 - 60
15 u = 3240
1 u = 3240 ÷ 15 = 216
Total number of coins
= 1 u + (1 u + 6)
= 2 u + 6
= 2 x 216 + 6
= 432 + 6
= 438
Answer(s): 438
