There were 7 more 5-cent coins than 50-cent coins in a wallet. Given that the value of all the 50-cent coins were $9.55 more than the value of all the 5-cent coins, how many 5-cent coins were there in the wallet?
|
50-cent |
5-cent |
Difference |
Number |
1 u |
1 u + 7 |
|
Value |
0.50 |
0.05 |
|
Total value |
0.5 u |
0.05 u + 0.35 |
0.45 u - 0.35 |
Total value of 50-cent coins
= 1 u x 0.50
= 0.5 u
Total value of 5-cent coins
= 0.05 x (1 u + 7)
= 0.05 u + 0.35
Total value of the 50-cent coins that is more than the total value of the 5-cent coins
= 0.5 u - (0.05 u + 0.35)
= 0.5 u - 0.05 u - 0.35
= 0.45 u - 0.35
0.45 u - 0.35 = 9.55
0.45 u = 9.55 + 0.35
0.45 u = 9.90
1 u = 9.90 ÷ 0.45 = 22
Number of 5-cent coins
= 1 u + 7
= 22 + 7
= 29
Answer(s): 29