Yoko had an equal number of $2 and $20 notes. After spending 40 pieces of $20 and 36 pieces of $2 notes, the ratio of the $2 notes to $20 notes left was 7 : 5. Find the value of the notes left.
| |
$2 |
$20 |
| Before |
7 u + 36 |
5 u + 40 |
| Change |
- 36 |
- 40 |
| After |
7 u |
5 u |
Number of $2 notes at first = 7 u + 36
Number of $20 notes at first = 5 u + 40
The number of $2 and $20 notes at first is the same.
7 u + 36 = 5 u + 40
7 u - 5 u = 40 - 36
2 u = 4
1 u = 4 ÷ 2 = 2
Value of $2-notes left
= 7 u x 2
= 7 x 2 x 2
= $28
Value of $20-notes left
= 5 u x 20
= 5 x 2 x 20
= $200
Value of notes left
= 28 + 200
= $228
Answer(s): $228
