The number of five-cent coins in a pouch was
14 the number of ten-cent coins. Julian took out 18 ten-cent coins and exchanged them for five-cent coins. Then he put the money back into the pouch. The number of ten-cent coins became
25 the number of five-cent coins. How much money was there in the pouch?
|
Make u the same (1)x4 = (3) |
5-cent (1) |
10-cent (2) |
Before |
4 u |
1 u |
4 u |
Change |
+ 144 |
+ 36 |
- 18 |
After |
20 p |
5 p |
2 p |
Value of 10-cent coins to be exchanged to 5-cent coins
= 18 x 10
= 180
Number of 5-cent coins to be exchanged from the 10-cent coins
= 180 ÷ 5
= 36
(3) = (2)
20 p - 144 = 2 p + 18
20 p - 2 p = 18 + 144
18 p = 162
1 p = 162 ÷ 18 = 9
Number of 5-cent coins in the end
= 5 p
= 5 p x 9
= 45
Value of 5-cent coins in the end
= 45 x 5
= 225¢
Number of 10-cent coins in the end
= 2 p
= 2 x 9
= 18
Value of 10-cent coins in the end
= 18 x 10
= 180¢
Total value of coins
= 225 + 180
= 405¢
$1 = 100¢
405¢ = $4.05
Answer(s): $4.05