The ratio of the number of $20-notes to $50-notes in Winnie's purse was 1 : 5. Winnie exchanged 8 pieces of $50-notes for $20-notes. She then had an equal number of $20-notes and $50-notes. What was the total value of $20-notes and $50-notes in Winnie's purse at first?
| |
$20-notes |
$50-notes |
| Before |
1 u |
5 u |
| Change |
+ 20 |
- 8 |
| After |
1 u + 20 |
5 u - 8 |
Value of 8 pieces of $50-notes
= 8 x 50
= $400
Number of $20-notes that Winnie exchanged for
= 400 ÷ 20
= 20
After the exchange, Winnie had an equal number of $20-notes and $50-notes.
5 u - 8 = 1 u + 20
5 u - 1 u = 20 + 8
4 u = 28
1 u = 28 ÷ 4 = 7
Number of $20-notes at first
= 1 u
= 7
Value of $20-notes at first
= 7 x 20
= $140
Number of $50-notes at first
= 5 u
= 5 x 7
= 35
Value of $50-notes at first
= 35 x 50
= $1750
Total value of $20-notes and $50-notes at first
= 140 + 1750
= $1890
Answer(s): $1890
