A jar contained $5 and $10 notes with a total value of $390. 12 pieces of $10 were exchanged for $5 notes of similar value. In the end, the number of $5 notes was the same as the $10 notes. How many $5 notes were there at first?
| |
$5 |
$10 |
| Before |
1 u - 24 |
1 u + 12 |
| Change |
+ 24 |
- 12 |
| After |
1 u |
1 u |
Total value of $5 and $10 notes remains unchanged after the exchange of notes of similar value.
Total value of 12 pieces of $10-notes
= 12 x 10
= $120
Number of $5-notes that 12 pieces of $10-notes were exchanged for
= 120 ÷ 5
= 24
| In the end |
$5 |
$10 |
Total |
| Number |
1 u |
1 u |
2 u |
| Value |
5 |
10 |
|
| Total Value |
5 u |
10 u |
15 u |
Total value of $5 and $10 notes
= 5 u + 10 u
= 15 u
15 u = 390
1 u = 390 ÷ 15 = 26
Number of $5 notes at first
= 1 u - 24
= 26 - 24
= 2
Answer(s): 2
