The number of five-cent coins in a pouch was
14 the number of twenty-cent coins. Ivan took out 23 twenty-cent coins and exchanged them for five-cent coins. Then he put the money back into the pouch. The number of twenty-cent coins became
35 the number of five-cent coins. How much money was there in the pouch?
|
Make u the same (1)x4 = (3) |
5-cent (1) |
20-cent (2) |
Before |
4 u |
1 u |
4 u |
Change |
+ 368 |
+ 92 |
- 23 |
After |
20 p |
5 p |
3 p |
Value of 20-cent coins to be exchanged to 5-cent coins
= 23 x 20
= 460
Number of 5-cent coins to be exchanged from the 20-cent coins
= 460 ÷ 5
= 92
(3) = (2)
20 p - 368 = 3 p + 23
20 p - 3 p = 23 + 368
17 p = 391
1 p = 391 ÷ 17 = 23
Number of 5-cent coins in the end
= 5 p
= 5 p x 23
= 115
Value of 5-cent coins in the end
= 115 x 5
= 575¢
Number of 20-cent coins in the end
= 3 p
= 3 x 23
= 69
Value of 20-cent coins in the end
= 69 x 20
= 1380¢
Total value of coins
= 575 + 1380
= 1955¢
$1 = 100¢
1955¢ = $19.55
Answer(s): $19.55