The ratio of the number of $10-notes to $50-notes in Zoe's handbag was 1 : 4. Zoe exchanged 5 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 Zoe's handbag at first?
|
$10-notes |
$50-notes |
Before |
1 u |
4 u |
Change |
+ 25 |
- 5 |
After |
1 u + 25 |
4 u - 5 |
Value of 5 pieces of $50-notes
= 5 x 50
= $250
Number of $10-notes that Zoe exchanged for
= 250 ÷ 10
= 25
After the exchange, Zoe had an equal number of $10-notes and $50-notes.
4 u - 5 = 1 u + 25
4 u - 1 u = 25 + 5
3 u = 30
1 u = 30 ÷ 3 = 10
Number of $10-notes at first
= 1 u
= 10
Value of $10-notes at first
= 10 x 10
= $100
Number of $50-notes at first
= 4 u
= 4 x 10
= 40
Value of $50-notes at first
= 40 x 50
= $2000
Total value of $10-notes and $50-notes at first
= 100 + 2000
= $2100
Answer(s): $2100