The ratio of the number of $10-notes to $50-notes in Gwen's wallet was 1 : 8. Gwen exchanged 7 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 Gwen's wallet at first?
|
$10-notes |
$50-notes |
Before |
1 u |
8 u |
Change |
+ 35 |
- 7 |
After |
1 u + 35 |
8 u - 7 |
Value of 7 pieces of $50-notes
= 7 x 50
= $350
Number of $10-notes that Gwen exchanged for
= 350 ÷ 10
= 35
After the exchange, Gwen had an equal number of $10-notes and $50-notes.
8 u - 7 = 1 u + 35
8 u - 1 u = 35 + 7
7 u = 42
1 u = 42 ÷ 7 = 6
Number of $10-notes at first
= 1 u
= 6
Value of $10-notes at first
= 6 x 10
= $60
Number of $50-notes at first
= 8 u
= 8 x 6
= 48
Value of $50-notes at first
= 48 x 50
= $2400
Total value of $10-notes and $50-notes at first
= 60 + 2400
= $2460
Answer(s): $2460