Esther had an equal number of $20 and $50 notes. After spending 33 pieces of $50 and 12 pieces of $20 notes, the ratio of the $20 notes to $50 notes left was 7 : 4. Find the value of the notes left.
| |
$20 |
$50 |
| Before |
7 u + 12 |
4 u + 33 |
| Change |
- 12 |
- 33 |
| After |
7 u |
4 u |
Number of $20 notes at first = 7 u + 12
Number of $50 notes at first = 4 u + 33
The number of $20 and $50 notes at first is the same.
7 u + 12 = 4 u + 33
7 u - 4 u = 33 - 12
3 u = 21
1 u = 21 ÷ 3 = 7
Value of $20-notes left
= 7 u x 20
= 7 x 7 x 20
= $980
Value of $50-notes left
= 4 u x 50
= 4 x 7 x 50
= $1400
Value of notes left
= 980 + 1400
= $2380
Answer(s): $2380
