The ratio of the number of $5-notes to $20-notes in Pamela's handbag was 1 : 6. Pamela exchanged 6 pieces of $20-notes for $5-notes. She then had an equal number of $5-notes and $20-notes. What was the total value of $5-notes and $20-notes in Pamela's handbag at first?
| |
$5-notes |
$20-notes |
| Before |
1 u |
6 u |
| Change |
+ 24 |
- 6 |
| After |
1 u + 24 |
6 u - 6 |
Value of 6 pieces of $20-notes
= 6 x 20
= $120
Number of $5-notes that Pamela exchanged for
= 120 ÷ 5
= 24
After the exchange, Pamela had an equal number of $5-notes and $20-notes.
6 u - 6 = 1 u + 24
6 u - 1 u = 24 + 6
5 u = 30
1 u = 30 ÷ 5 = 6
Number of $5-notes at first
= 1 u
= 6
Value of $5-notes at first
= 6 x 5
= $30
Number of $20-notes at first
= 6 u
= 6 x 6
= 36
Value of $20-notes at first
= 36 x 20
= $720
Total value of $5-notes and $20-notes at first
= 30 + 720
= $750
Answer(s): $750
