A jar contained $5 and $20 notes with a total value of $725. 4 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 $5 notes were there at first?
| |
$5 |
$20 |
| Before |
1 u - 16 |
1 u + 4 |
| Change |
+ 16 |
- 4 |
| 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 4 pieces of $20-notes
= 4 x 20
= $80
Number of $5-notes that 4 pieces of $20-notes were exchanged for
= 80 ÷ 5
= 16
| 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 = 725
1 u = 725 ÷ 25 = 29
Number of $5 notes at first
= 1 u - 16
= 29 - 16
= 13
Answer(s): 13
