Penelope had an equal number of $10 and $20 notes. After spending 50 pieces of $20 and 38 pieces of $10 notes, the ratio of the $10 notes to $20 notes left was 5 : 2. Find the value of the notes left.
| |
$10 |
$20 |
| Before |
5 u + 38 |
2 u + 50 |
| Change |
- 38 |
- 50 |
| After |
5 u |
2 u |
Number of $10 notes at first = 5 u + 38
Number of $20 notes at first = 2 u + 50
The number of $10 and $20 notes at first is the same.
5 u + 38 = 2 u + 50
5 u - 2 u = 50 - 38
3 u = 12
1 u = 12 ÷ 3 = 4
Value of $10-notes left
= 5 u x 10
= 5 x 4 x 10
= $200
Value of $20-notes left
= 2 u x 20
= 2 x 4 x 20
= $160
Value of notes left
= 200 + 160
= $360
Answer(s): $360
