The number of five-cent coins in a tin can was
14 the number of twenty-cent coins. Archie took out 17 twenty-cent coins and exchanged them for five-cent coins. Then he put the money back into the tin can. The number of twenty-cent coins became
35 the number of five-cent coins. How much money was there in the tin can?
|
Make u the same (1)x4 = (3) |
5-cent (1) |
20-cent (2) |
Before |
4 u |
1 u |
4 u |
Change |
+ 272 |
+ 68 |
- 17 |
After |
20 p |
5 p |
3 p |
Value of 20-cent coins to be exchanged to 5-cent coins
= 17 x 20
= 340
Number of 5-cent coins to be exchanged from the 20-cent coins
= 340 ÷ 5
= 68
(3) = (2)
20 p - 272 = 3 p + 17
20 p - 3 p = 17 + 272
17 p = 289
1 p = 289 ÷ 17 = 17
Number of 5-cent coins in the end
= 5 p
= 5 p x 17
= 85
Value of 5-cent coins in the end
= 85 x 5
= 425¢
Number of 20-cent coins in the end
= 3 p
= 3 x 17
= 51
Value of 20-cent coins in the end
= 51 x 20
= 1020¢
Total value of coins
= 425 + 1020
= 1445¢
$1 = 100¢
1445¢ = $14.45
Answer(s): $14.45