A jar contained $20 and $2 notes with a total value of $462. 10 pieces of $2 were exchanged for $20 notes of similar value. In the end, the number of $20 notes was the same as the $2 notes. How many $20 notes were there at first?
|
$20 |
$2 |
Before |
1 u - 1 |
1 u + 10 |
Change |
+ 1 |
- 10 |
After |
1 u |
1 u |
Total value of $20 and $2 notes remains unchanged after the exchange of notes of similar value.
Total value of 10 pieces of $2-notes
= 10 x 2
= $20
Number of $20-notes that 10 pieces of $2-notes were exchanged for
= 20 ÷ 20
= 1
In the end |
$20 |
$2 |
Total |
Number |
1 u |
1 u |
2 u |
Value |
20 |
2 |
|
Total Value |
20 u |
2 u |
22 u |
Total value of $20 and $2 notes
= 20 u + 2 u
= 22 u
22 u = 462
1 u = 462 ÷ 22 = 21
Number of $20 notes at first
= 1 u - 1
= 21 - 1
= 20
Answer(s): 20