Zara had an equal number of $10 and $20 notes. After spending 47 pieces of $20 and 41 pieces of $10 notes, the ratio of the $10 notes to $20 notes left was 8 : 5. Find the value of the notes left.
| |
$10 |
$20 |
| Before |
8 u + 41 |
5 u + 47 |
| Change |
- 41 |
- 47 |
| After |
8 u |
5 u |
Number of $10 notes at first = 8 u + 41
Number of $20 notes at first = 5 u + 47
The number of $10 and $20 notes at first is the same.
8 u + 41 = 5 u + 47
8 u - 5 u = 47 - 41
3 u = 6
1 u = 6 ÷ 3 = 2
Value of $10-notes left
= 8 u x 10
= 8 x 2 x 10
= $160
Value of $20-notes left
= 5 u x 20
= 5 x 2 x 20
= $200
Value of notes left
= 160 + 200
= $360
Answer(s): $360
