Penelope had an equal number of $5 and $10 notes. After spending 34 pieces of $10 and 22 pieces of $5 notes, the ratio of the $5 notes to $10 notes left was 7 : 1. Find the value of the notes left.
| |
$5 |
$10 |
| Before |
7 u + 22 |
1 u + 34 |
| Change |
- 22 |
- 34 |
| After |
7 u |
1 u |
Number of $5 notes at first = 7 u + 22
Number of $10 notes at first = 1 u + 34
The number of $5 and $10 notes at first is the same.
7 u + 22 = 1 u + 34
7 u - 1 u = 34 - 22
6 u = 12
1 u = 12 ÷ 6 = 2
Value of $5-notes left
= 7 u x 5
= 7 x 2 x 5
= $70
Value of $10-notes left
= 1 u x 10
= 1 x 2 x 10
= $20
Value of notes left
= 70 + 20
= $90
Answer(s): $90
