A jar contained $5 and $20 notes with a total value of $325. 7 pieces of $20 were exchanged for $5 notes of similar value. In the end, the number of $5 notes was the same as the $20 notes. How many $20 notes were there at first?
|
$5 |
$20 |
Before |
1 u - 28 |
1 u + 7 |
Change |
+ 28 |
- 7 |
After |
1 u |
1 u |
Total value of $5 and $20 notes remains unchanged after the exchange of notes of similar value.
Total value of 7 pieces of $20-notes
= 7 x 20
= $140
Number of $5-notes that 7 pieces of $20-notes were exchanged for
= 140 ÷ 5
= 28
In the end |
$5 |
$20 |
Total |
Number |
1 u |
1 u |
2 u |
Value |
5 |
20 |
|
Total Value |
5 u |
20 u |
25 u |
Total value of $5 and $20 notes
= 5 u + 20 u
= 25 u
25 u = 325
1 u = 325 ÷ 25 = 13
Number of $20 notes at first
= 1 u + 7
= 13 + 7
= 20
Answer(s): 20