A jar contained $2 and $10 notes with a total value of $168. 9 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 $10 notes were there at first?
|
$2 |
$10 |
Before |
1 u - 45 |
1 u + 9 |
Change |
+ 45 |
- 9 |
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 9 pieces of $10-notes
= 9 x 10
= $90
Number of $2-notes that 9 pieces of $10-notes were exchanged for
= 90 ÷ 2
= 45
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 = 168
1 u = 168 ÷ 12 = 14
Number of $10 notes at first
= 1 u + 9
= 14 + 9
= 23
Answer(s): 23