Olivia had an equal number of $10 and $1 notes. After spending 40 pieces of $1 and 33 pieces of $10 notes, the ratio of the $10 notes to $1 notes left was 8 : 1. Find the value of the notes left.
| |
$10 |
$1 |
| Before |
8 u + 33 |
1 u + 40 |
| Change |
- 33 |
- 40 |
| After |
8 u |
1 u |
Number of $10 notes at first = 8 u + 33
Number of $1 notes at first = 1 u + 40
The number of $10 and $1 notes at first is the same.
8 u + 33 = 1 u + 40
8 u - 1 u = 40 - 33
7 u = 7
1 u = 7 ÷ 7 = 1
Value of $10-notes left
= 8 u x 10
= 8 x 1 x 10
= $80
Value of $1-notes left
= 1 u x 1
= 1 x 1 x 1
= $1
Value of notes left
= 80 + 1
= $81
Answer(s): $81
