Yen had an equal number of $1 and $10 notes. After spending 43 pieces of $10 and 28 pieces of $1 notes, the ratio of the $1 notes to $10 notes left was 4 : 1. Find the value of the notes left.
| |
$1 |
$10 |
| Before |
4 u + 28 |
1 u + 43 |
| Change |
- 28 |
- 43 |
| After |
4 u |
1 u |
Number of $1 notes at first = 4 u + 28
Number of $10 notes at first = 1 u + 43
The number of $1 and $10 notes at first is the same.
4 u + 28 = 1 u + 43
4 u - 1 u = 43 - 28
3 u = 15
1 u = 15 ÷ 3 = 5
Value of $1-notes left
= 4 u x 1
= 4 x 5 x 1
= $20
Value of $10-notes left
= 1 u x 10
= 1 x 5 x 10
= $50
Value of notes left
= 20 + 50
= $70
Answer(s): $70
