In a bag of notes, the number of $10, $20 and $100 are in ratio of 7 : 1 : 7.
37 of the $10-notes and 15 $20-notes are taken out. The remaining notes are worth $2740. Find the difference between the value of $100-notes and $10-notes in the end.
| |
$10 |
$20 |
$100 |
| Before |
7 u |
1 u |
7 u |
| Change |
- 3 u |
- 15 |
|
| After |
4 u |
1 u - 15 |
7 u |
| |
$10 |
$20 |
$100 |
Total |
| Number |
4 u |
1 u - 15 |
7 u |
|
| Value |
10 |
20 |
100 |
|
| Total value |
40 u |
20 u - 300 |
700 u |
2740 |
Total value of the notes
= 40 u + 20 u - 300 + 700 u
= 760 u - 300
760 u - 300 = 2740
760 u = 2740 + 300
760 u = 3040
1 u = 3040 ÷ 760 = 4
Difference between the value of $100-notes and $10-notes in the end
= 700 u - 40 u
= 660 u
= 660 x 4
= $2640
Answer(s): $2640
