The ratio of the number of $2-notes to $10-notes in Jaslyn's wallet was 1 : 3. Jaslyn exchanged 9 pieces of $10-notes for $2-notes. She then had an equal number of $2-notes and $10-notes. What was the total value of $2-notes and $10-notes in Jaslyn's wallet at first?
|
$2-notes |
$10-notes |
Before |
1 u |
3 u |
Change |
+ 45 |
- 9 |
After |
1 u + 45 |
3 u - 9 |
Value of 9 pieces of $10-notes
= 9 x 10
= $90
Number of $2-notes that Jaslyn exchanged for
= 90 ÷ 2
= 45
After the exchange, Jaslyn had an equal number of $2-notes and $10-notes.
3 u - 9 = 1 u + 45
3 u - 1 u = 45 + 9
2 u = 54
1 u = 54 ÷ 2 = 27
Number of $2-notes at first
= 1 u
= 27
Value of $2-notes at first
= 27 x 2
= $54
Number of $10-notes at first
= 3 u
= 3 x 27
= 81
Value of $10-notes at first
= 81 x 10
= $810
Total value of $2-notes and $10-notes at first
= 54 + 810
= $864
Answer(s): $864