The ratio of the number of $5-notes to $50-notes in Jean's purse was 1 : 4. Jean exchanged 9 pieces of $50-notes for $5-notes. She then had an equal number of $5-notes and $50-notes. What was the total value of $5-notes and $50-notes in Jean's purse at first?
|
$5-notes |
$50-notes |
Before |
1 u |
4 u |
Change |
+ 90 |
- 9 |
After |
1 u + 90 |
4 u - 9 |
Value of 9 pieces of $50-notes
= 9 x 50
= $450
Number of $5-notes that Jean exchanged for
= 450 ÷ 5
= 90
After the exchange, Jean had an equal number of $5-notes and $50-notes.
4 u - 9 = 1 u + 90
4 u - 1 u = 90 + 9
3 u = 99
1 u = 99 ÷ 3 = 33
Number of $5-notes at first
= 1 u
= 33
Value of $5-notes at first
= 33 x 5
= $165
Number of $50-notes at first
= 4 u
= 4 x 33
= 132
Value of $50-notes at first
= 132 x 50
= $6600
Total value of $5-notes and $50-notes at first
= 165 + 6600
= $6765
Answer(s): $6765