Gabby had an equal number of $100 and $10 notes. After spending 30 pieces of $10 and 12 pieces of $100 notes, the ratio of the $100 notes to $10 notes left was 7 : 5. Find the value of the notes left.
| |
$100 |
$10 |
| Before |
7 u + 12 |
5 u + 30 |
| Change |
- 12 |
- 30 |
| After |
7 u |
5 u |
Number of $100 notes at first = 7 u + 12
Number of $10 notes at first = 5 u + 30
The number of $100 and $10 notes at first is the same.
7 u + 12 = 5 u + 30
7 u - 5 u = 30 - 12
2 u = 18
1 u = 18 ÷ 2 = 9
Value of $100-notes left
= 7 u x 100
= 7 x 9 x 100
= $6300
Value of $10-notes left
= 5 u x 10
= 5 x 9 x 10
= $450
Value of notes left
= 6300 + 450
= $6750
Answer(s): $6750
