Shiyun had an equal number of $10 and $5 notes. After spending 34 pieces of $5 and 31 pieces of $10 notes, the ratio of the $10 notes to $5 notes left was 5 : 2. Find the value of the notes left.
| |
$10 |
$5 |
| Before |
5 u + 31 |
2 u + 34 |
| Change |
- 31 |
- 34 |
| After |
5 u |
2 u |
Number of $10 notes at first = 5 u + 31
Number of $5 notes at first = 2 u + 34
The number of $10 and $5 notes at first is the same.
5 u + 31 = 2 u + 34
5 u - 2 u = 34 - 31
3 u = 3
1 u = 3 ÷ 3 = 1
Value of $10-notes left
= 5 u x 10
= 5 x 1 x 10
= $50
Value of $5-notes left
= 2 u x 5
= 2 x 1 x 5
= $10
Value of notes left
= 50 + 10
= $60
Answer(s): $60
