Erika had an equal number of $2 and $5 notes. After spending 31 pieces of $5 and 17 pieces of $2 notes, the ratio of the $2 notes to $5 notes left was 8 : 1. Find the value of the notes left.
| |
$2 |
$5 |
| Before |
8 u + 17 |
1 u + 31 |
| Change |
- 17 |
- 31 |
| After |
8 u |
1 u |
Number of $2 notes at first = 8 u + 17
Number of $5 notes at first = 1 u + 31
The number of $2 and $5 notes at first is the same.
8 u + 17 = 1 u + 31
8 u - 1 u = 31 - 17
7 u = 14
1 u = 14 ÷ 7 = 2
Value of $2-notes left
= 8 u x 2
= 8 x 2 x 2
= $32
Value of $5-notes left
= 1 u x 5
= 1 x 2 x 5
= $10
Value of notes left
= 32 + 10
= $42
Answer(s): $42
