Zane has 5-cent coins and 10-cent coins. The total value of all his coins is $14. He has 11 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 + 11 |
2 u + 11 |
| Value |
5 |
10 |
|
| Total value |
5 u |
10 u + 110 |
15 u + 110 |
$1 = 100¢
$14 = 14 x 100 = 1400¢
Zane has 11 more 10-cent coins than 5-cent coins.
Number of 5-cent coins = 1 u
Number of 10-cent coins = 1 u + 11
Total value of 5-cent coins
= 5 x 1 u
= 5 u
Total value of 10-cent coins
= 10 x (1 u + 11)
= 10 u + 110
Total value of the coins
= 5 u + 10 u + 110
= 15 u + 110
15 u + 110 = 1400
15 u = 1400 - 110
15 u = 1290
1 u = 1290 ÷ 15 = 86
Total number of coins
= 1 u + (1 u + 11)
= 2 u + 11
= 2 x 86 + 11
= 172 + 11
= 183
Answer(s): 183
