The number of five-cent coins in a jar was
13 the number of twenty-cent coins. Archie took out 22 twenty-cent coins and exchanged them for five-cent coins. Then he put the money back into the jar. The number of twenty-cent coins became
25 the number of five-cent coins. How much money was there in the jar?
|
Make u the same (1)x3 = (3) |
5-cent (1) |
20-cent (2) |
Before |
3 u |
1 u |
3 u |
Change |
+ 264 |
+ 88 |
- 22 |
After |
15 p |
5 p |
2 p |
Value of 20-cent coins to be exchanged to 5-cent coins
= 22 x 20
= 440
Number of 5-cent coins to be exchanged from the 20-cent coins
= 440 ÷ 5
= 88
(3) = (2)
15 p - 264 = 2 p + 22
15 p - 2 p = 22 + 264
13 p = 286
1 p = 286 ÷ 13 = 22
Number of 5-cent coins in the end
= 5 p
= 5 p x 22
= 110
Value of 5-cent coins in the end
= 110 x 5
= 550¢
Number of 20-cent coins in the end
= 2 p
= 2 x 22
= 44
Value of 20-cent coins in the end
= 44 x 20
= 880¢
Total value of coins
= 550 + 880
= 1430¢
$1 = 100¢
1430¢ = $14.30
Answer(s): $14.30