Wendy had an equal number of $10 and $20 notes. After spending 48 pieces of $20 and 28 pieces of $10 notes, the ratio of the $10 notes to $20 notes left was 7 : 3. Find the value of the notes left.
| |
$10 |
$20 |
| Before |
7 u + 28 |
3 u + 48 |
| Change |
- 28 |
- 48 |
| After |
7 u |
3 u |
Number of $10 notes at first = 7 u + 28
Number of $20 notes at first = 3 u + 48
The number of $10 and $20 notes at first is the same.
7 u + 28 = 3 u + 48
7 u - 3 u = 48 - 28
4 u = 20
1 u = 20 ÷ 4 = 5
Value of $10-notes left
= 7 u x 10
= 7 x 5 x 10
= $350
Value of $20-notes left
= 3 u x 20
= 3 x 5 x 20
= $300
Value of notes left
= 350 + 300
= $650
Answer(s): $650
