A jar contained $2 and $10 notes with a total value of $408. 4 pieces of $10 were exchanged for $2 notes of similar value. In the end, the number of $2 notes was the same as the $10 notes. How many $2 notes were there at first?
|
$2 |
$10 |
Before |
1 u - 20 |
1 u + 4 |
Change |
+ 20 |
- 4 |
After |
1 u |
1 u |
Total value of $2 and $10 notes remains unchanged after the exchange of notes of similar value.
Total value of 4 pieces of $10-notes
= 4 x 10
= $40
Number of $2-notes that 4 pieces of $10-notes were exchanged for
= 40 ÷ 2
= 20
In the end |
$2 |
$10 |
Total |
Number |
1 u |
1 u |
2 u |
Value |
2 |
10 |
|
Total Value |
2 u |
10 u |
12 u |
Total value of $2 and $10 notes
= 2 u + 10 u
= 12 u
12 u = 408
1 u = 408 ÷ 12 = 34
Number of $2 notes at first
= 1 u - 20
= 34 - 20
= 14
Answer(s): 14