Risa had an equal number of $10 and $2 notes. After spending 46 pieces of $2 and 40 pieces of $10 notes, the ratio of the $10 notes to $2 notes left was 8 : 5. Find the value of the notes left.
| |
$10 |
$2 |
| Before |
8 u + 40 |
5 u + 46 |
| Change |
- 40 |
- 46 |
| After |
8 u |
5 u |
Number of $10 notes at first = 8 u + 40
Number of $2 notes at first = 5 u + 46
The number of $10 and $2 notes at first is the same.
8 u + 40 = 5 u + 46
8 u - 5 u = 46 - 40
3 u = 6
1 u = 6 ÷ 3 = 2
Value of $10-notes left
= 8 u x 10
= 8 x 2 x 10
= $160
Value of $2-notes left
= 5 u x 2
= 5 x 2 x 2
= $20
Value of notes left
= 160 + 20
= $180
Answer(s): $180
