Opal had an equal number of $10 and $1 notes. After spending 49 pieces of $1 and 25 pieces of $10 notes, the ratio of the $10 notes to $1 notes left was 5 : 3. Find the value of the notes left.
| |
$10 |
$1 |
| Before |
5 u + 25 |
3 u + 49 |
| Change |
- 25 |
- 49 |
| After |
5 u |
3 u |
Number of $10 notes at first = 5 u + 25
Number of $1 notes at first = 3 u + 49
The number of $10 and $1 notes at first is the same.
5 u + 25 = 3 u + 49
5 u - 3 u = 49 - 25
2 u = 24
1 u = 24 ÷ 2 = 12
Value of $10-notes left
= 5 u x 10
= 5 x 12 x 10
= $600
Value of $1-notes left
= 3 u x 1
= 3 x 12 x 1
= $36
Value of notes left
= 600 + 36
= $636
Answer(s): $636
