The ratio of the number of $5-notes to $50-notes in Xuan's bag was 1 : 5. Xuan exchanged 4 pieces of $50-notes for $5-notes. She then had an equal number of $5-notes and $50-notes. What was the total value of $5-notes and $50-notes in Xuan's bag at first?
| |
$5-notes |
$50-notes |
| Before |
1 u |
5 u |
| Change |
+ 40 |
- 4 |
| After |
1 u + 40 |
5 u - 4 |
Value of 4 pieces of $50-notes
= 4 x 50
= $200
Number of $5-notes that Xuan exchanged for
= 200 ÷ 5
= 40
After the exchange, Xuan had an equal number of $5-notes and $50-notes.
5 u - 4 = 1 u + 40
5 u - 1 u = 40 + 4
4 u = 44
1 u = 44 ÷ 4 = 11
Number of $5-notes at first
= 1 u
= 11
Value of $5-notes at first
= 11 x 5
= $55
Number of $50-notes at first
= 5 u
= 5 x 11
= 55
Value of $50-notes at first
= 55 x 50
= $2750
Total value of $5-notes and $50-notes at first
= 55 + 2750
= $2805
Answer(s): $2805
