Mary had an equal number of $20 and $1 notes. After spending 46 pieces of $1 and 16 pieces of $20 notes, the ratio of the $20 notes to $1 notes left was 7 : 5. Find the value of the notes left.
| |
$20 |
$1 |
| Before |
7 u + 16 |
5 u + 46 |
| Change |
- 16 |
- 46 |
| After |
7 u |
5 u |
Number of $20 notes at first = 7 u + 16
Number of $1 notes at first = 5 u + 46
The number of $20 and $1 notes at first is the same.
7 u + 16 = 5 u + 46
7 u - 5 u = 46 - 16
2 u = 30
1 u = 30 ÷ 2 = 15
Value of $20-notes left
= 7 u x 20
= 7 x 15 x 20
= $2100
Value of $1-notes left
= 5 u x 1
= 5 x 15 x 1
= $75
Value of notes left
= 2100 + 75
= $2175
Answer(s): $2175
