The number of five-cent coins in a coin box was
14 the number of twenty-cent coins. Julian took out 19 twenty-cent coins and exchanged them for five-cent coins. Then he put the money back into the coin box. The number of twenty-cent coins became
35 the number of five-cent coins. How much money was there in the coin box?
|
Make u the same (1)x4 = (3) |
5-cent (1) |
20-cent (2) |
Before |
4 u |
1 u |
4 u |
Change |
+ 304 |
+ 76 |
- 19 |
After |
20 p |
5 p |
3 p |
Value of 20-cent coins to be exchanged to 5-cent coins
= 19 x 20
= 380
Number of 5-cent coins to be exchanged from the 20-cent coins
= 380 ÷ 5
= 76
(3) = (2)
20 p - 304 = 3 p + 19
20 p - 3 p = 19 + 304
17 p = 323
1 p = 323 ÷ 17 = 19
Number of 5-cent coins in the end
= 5 p
= 5 p x 19
= 95
Value of 5-cent coins in the end
= 95 x 5
= 475¢
Number of 20-cent coins in the end
= 3 p
= 3 x 19
= 57
Value of 20-cent coins in the end
= 57 x 20
= 1140¢
Total value of coins
= 475 + 1140
= 1615¢
$1 = 100¢
1615¢ = $16.15
Answer(s): $16.15