The number of ten-cent coins in a bottle was
14 the number of twenty-cent coins. Cody took out 24 twenty-cent coins and exchanged them for ten-cent coins. Then he put the money back into the bottle. The number of twenty-cent coins became
58 the number of ten-cent coins. How much money was there in the bottle?
|
Make u the same (1)x4 = (3) |
10-cent (1) |
20-cent (2) |
Before |
4 u |
1 u |
4 u |
Change |
+ 192 |
+ 48 |
- 24 |
After |
32 p |
8 p |
5 p |
Value of 20-cent coins to be exchanged to 10-cent coins
= 24 x 20
= 480
Number of 10-cent coins to be exchanged from the 20-cent coins
= 480 ÷ 10
= 48
(3) = (2)
32 p - 192 = 5 p + 24
32 p - 5 p = 24 + 192
27 p = 216
1 p = 216 ÷ 27 = 8
Number of 10-cent coins in the end
= 8 p
= 8 p x 8
= 64
Value of 10-cent coins in the end
= 64 x 10
= 640¢
Number of 20-cent coins in the end
= 5 p
= 5 x 8
= 40
Value of 20-cent coins in the end
= 40 x 20
= 800¢
Total value of coins
= 640 + 800
= 1440¢
$1 = 100¢
1440¢ = $14.40
Answer(s): $14.40