The ratio of the number of $5-notes to $20-notes in Hilda's jar was 1 : 6. Hilda exchanged 12 pieces of $20-notes for $5-notes. She then had an equal number of $5-notes and $20-notes. What was the total value of $5-notes and $20-notes in Hilda's jar at first?
| |
$5-notes |
$20-notes |
| Before |
1 u |
6 u |
| Change |
+ 48 |
- 12 |
| After |
1 u + 48 |
6 u - 12 |
Value of 12 pieces of $20-notes
= 12 x 20
= $240
Number of $5-notes that Hilda exchanged for
= 240 ÷ 5
= 48
After the exchange, Hilda had an equal number of $5-notes and $20-notes.
6 u - 12 = 1 u + 48
6 u - 1 u = 48 + 12
5 u = 60
1 u = 60 ÷ 5 = 12
Number of $5-notes at first
= 1 u
= 12
Value of $5-notes at first
= 12 x 5
= $60
Number of $20-notes at first
= 6 u
= 6 x 12
= 72
Value of $20-notes at first
= 72 x 20
= $1440
Total value of $5-notes and $20-notes at first
= 60 + 1440
= $1500
Answer(s): $1500
