The ratio of the number of $20-notes to $50-notes in Jaslyn's handbag was 1 : 7. Jaslyn exchanged 12 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 Jaslyn's handbag at first?
| |
$20-notes |
$50-notes |
| Before |
1 u |
7 u |
| Change |
+ 30 |
- 12 |
| After |
1 u + 30 |
7 u - 12 |
Value of 12 pieces of $50-notes
= 12 x 50
= $600
Number of $20-notes that Jaslyn exchanged for
= 600 ÷ 20
= 30
After the exchange, Jaslyn had an equal number of $20-notes and $50-notes.
7 u - 12 = 1 u + 30
7 u - 1 u = 30 + 12
6 u = 42
1 u = 42 ÷ 6 = 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
= 7 u
= 7 x 7
= 49
Value of $50-notes at first
= 49 x 50
= $2450
Total value of $20-notes and $50-notes at first
= 140 + 2450
= $2590
Answer(s): $2590
