The ratio of the number of $5-notes to $10-notes in Victoria's handbag was 1 : 6. Victoria exchanged 10 pieces of $10-notes for $5-notes. She then had an equal number of $5-notes and $10-notes. What was the total value of $5-notes and $10-notes in Victoria's handbag at first?
| |
$5-notes |
$10-notes |
| Before |
1 u |
6 u |
| Change |
+ 20 |
- 10 |
| After |
1 u + 20 |
6 u - 10 |
Value of 10 pieces of $10-notes
= 10 x 10
= $100
Number of $5-notes that Victoria exchanged for
= 100 ÷ 5
= 20
After the exchange, Victoria had an equal number of $5-notes and $10-notes.
6 u - 10 = 1 u + 20
6 u - 1 u = 20 + 10
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 $10-notes at first
= 6 u
= 6 x 6
= 36
Value of $10-notes at first
= 36 x 10
= $360
Total value of $5-notes and $10-notes at first
= 30 + 360
= $390
Answer(s): $390
