A jar contained $20 and $50 notes with a total value of $1820. 4 pieces of $50 were exchanged for $20 notes of similar value. In the end, the number of $20 notes was the same as the $50 notes. How many $20 notes were there at first?
|
$20 |
$50 |
Before |
1 u - 10 |
1 u + 4 |
Change |
+ 10 |
- 4 |
After |
1 u |
1 u |
Total value of $20 and $50 notes remains unchanged after the exchange of notes of similar value.
Total value of 4 pieces of $50-notes
= 4 x 50
= $200
Number of $20-notes that 4 pieces of $50-notes were exchanged for
= 200 ÷ 20
= 10
In the end |
$20 |
$50 |
Total |
Number |
1 u |
1 u |
2 u |
Value |
20 |
50 |
|
Total Value |
20 u |
50 u |
70 u |
Total value of $20 and $50 notes
= 20 u + 50 u
= 70 u
70 u = 1820
1 u = 1820 ÷ 70 = 26
Number of $20 notes at first
= 1 u - 10
= 26 - 10
= 16
Answer(s): 16