The ratio of the number of $10-notes to $50-notes in Jaslyn's jar was 1 : 4. Jaslyn exchanged 9 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 Jaslyn's jar at first?
| |
$10-notes |
$50-notes |
| Before |
1 u |
4 u |
| Change |
+ 45 |
- 9 |
| After |
1 u + 45 |
4 u - 9 |
Value of 9 pieces of $50-notes
= 9 x 50
= $450
Number of $10-notes that Jaslyn exchanged for
= 450 ÷ 10
= 45
After the exchange, Jaslyn had an equal number of $10-notes and $50-notes.
4 u - 9 = 1 u + 45
4 u - 1 u = 45 + 9
3 u = 54
1 u = 54 ÷ 3 = 18
Number of $10-notes at first
= 1 u
= 18
Value of $10-notes at first
= 18 x 10
= $180
Number of $50-notes at first
= 4 u
= 4 x 18
= 72
Value of $50-notes at first
= 72 x 50
= $3600
Total value of $10-notes and $50-notes at first
= 180 + 3600
= $3780
Answer(s): $3780
