Tammy had an equal number of $5 and $20 notes. After spending 47 pieces of $20 and 11 pieces of $5 notes, the ratio of the $5 notes to $20 notes left was 7 : 4. Find the value of the notes left.
| |
$5 |
$20 |
| Before |
7 u + 11 |
4 u + 47 |
| Change |
- 11 |
- 47 |
| After |
7 u |
4 u |
Number of $5 notes at first = 7 u + 11
Number of $20 notes at first = 4 u + 47
The number of $5 and $20 notes at first is the same.
7 u + 11 = 4 u + 47
7 u - 4 u = 47 - 11
3 u = 36
1 u = 36 ÷ 3 = 12
Value of $5-notes left
= 7 u x 5
= 7 x 12 x 5
= $420
Value of $20-notes left
= 4 u x 20
= 4 x 12 x 20
= $960
Value of notes left
= 420 + 960
= $1380
Answer(s): $1380
