Jean had an equal number of $1 and $20 notes. After spending 36 pieces of $20 and 24 pieces of $1 notes, the ratio of the $1 notes to $20 notes left was 7 : 1. Find the value of the notes left.
| |
$1 |
$20 |
| Before |
7 u + 24 |
1 u + 36 |
| Change |
- 24 |
- 36 |
| After |
7 u |
1 u |
Number of $1 notes at first = 7 u + 24
Number of $20 notes at first = 1 u + 36
The number of $1 and $20 notes at first is the same.
7 u + 24 = 1 u + 36
7 u - 1 u = 36 - 24
6 u = 12
1 u = 12 ÷ 6 = 2
Value of $1-notes left
= 7 u x 1
= 7 x 2 x 1
= $14
Value of $20-notes left
= 1 u x 20
= 1 x 2 x 20
= $40
Value of notes left
= 14 + 40
= $54
Answer(s): $54
