Winnie had an equal number of $20 and $1 notes. After spending 39 pieces of $1 and 29 pieces of $20 notes, the ratio of the $20 notes to $1 notes left was 3 : 1. Find the value of the notes left.
| |
$20 |
$1 |
| Before |
3 u + 29 |
1 u + 39 |
| Change |
- 29 |
- 39 |
| After |
3 u |
1 u |
Number of $20 notes at first = 3 u + 29
Number of $1 notes at first = 1 u + 39
The number of $20 and $1 notes at first is the same.
3 u + 29 = 1 u + 39
3 u - 1 u = 39 - 29
2 u = 10
1 u = 10 ÷ 2 = 5
Value of $20-notes left
= 3 u x 20
= 3 x 5 x 20
= $300
Value of $1-notes left
= 1 u x 1
= 1 x 5 x 1
= $5
Value of notes left
= 300 + 5
= $305
Answer(s): $305
