The ratio of the number of $10-notes to $50-notes in Joelle's purse was 1 : 6. Joelle exchanged 15 pieces of $50-notes for $10-notes. She then had an equal number of $10-notes and $50-notes. What was the total value of $10-notes and $50-notes in Joelle's purse at first?
|
$10-notes |
$50-notes |
Before |
1 u |
6 u |
Change |
+ 75 |
- 15 |
After |
1 u + 75 |
6 u - 15 |
Value of 15 pieces of $50-notes
= 15 x 50
= $750
Number of $10-notes that Joelle exchanged for
= 750 ÷ 10
= 75
After the exchange, Joelle had an equal number of $10-notes and $50-notes.
6 u - 15 = 1 u + 75
6 u - 1 u = 75 + 15
5 u = 90
1 u = 90 ÷ 5 = 18
Number of $10-notes at first
= 1 u
= 18
Value of $10-notes at first
= 18 x 10
= $180
Number of $50-notes at first
= 6 u
= 6 x 18
= 108
Value of $50-notes at first
= 108 x 50
= $5400
Total value of $10-notes and $50-notes at first
= 180 + 5400
= $5580
Answer(s): $5580