Abi had an equal number of $5 and $20 notes. After spending 41 pieces of $20 and 23 pieces of $5 notes, the ratio of the $5 notes to $20 notes left was 3 : 1. Find the value of the notes left.
| |
$5 |
$20 |
| Before |
3 u + 23 |
1 u + 41 |
| Change |
- 23 |
- 41 |
| After |
3 u |
1 u |
Number of $5 notes at first = 3 u + 23
Number of $20 notes at first = 1 u + 41
The number of $5 and $20 notes at first is the same.
3 u + 23 = 1 u + 41
3 u - 1 u = 41 - 23
2 u = 18
1 u = 18 ÷ 2 = 9
Value of $5-notes left
= 3 u x 5
= 3 x 9 x 5
= $135
Value of $20-notes left
= 1 u x 20
= 1 x 9 x 20
= $180
Value of notes left
= 135 + 180
= $315
Answer(s): $315
