The ratio of the number of $10-notes to $50-notes in Ivory's purse was 1 : 5. Ivory exchanged 4 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 Ivory's purse at first?
| |
$10-notes |
$50-notes |
| Before |
1 u |
5 u |
| Change |
+ 20 |
- 4 |
| After |
1 u + 20 |
5 u - 4 |
Value of 4 pieces of $50-notes
= 4 x 50
= $200
Number of $10-notes that Ivory exchanged for
= 200 ÷ 10
= 20
After the exchange, Ivory had an equal number of $10-notes and $50-notes.
5 u - 4 = 1 u + 20
5 u - 1 u = 20 + 4
4 u = 24
1 u = 24 ÷ 4 = 6
Number of $10-notes at first
= 1 u
= 6
Value of $10-notes at first
= 6 x 10
= $60
Number of $50-notes at first
= 5 u
= 5 x 6
= 30
Value of $50-notes at first
= 30 x 50
= $1500
Total value of $10-notes and $50-notes at first
= 60 + 1500
= $1560
Answer(s): $1560
