In a pouch of notes, the number of $20, $50 and $100 are in ratio of 5 : 4 : 2.
35 of the $20-notes and 7 $50-notes are taken out. The remaining notes are worth $1410. Find the difference between the value of $100-notes and $20-notes in the end.
|
$20 |
$50 |
$100 |
Before |
5 u |
4 u |
2 u |
Change |
- 3 u |
- 7 |
|
After |
2 u |
4 u - 7 |
2 u |
|
$20 |
$50 |
$100 |
Total |
Number |
2 u |
4 u - 7 |
2 u |
|
Value |
20 |
50 |
100 |
|
Total value |
40 u |
200 u - 350 |
200 u |
1410 |
Total value of the notes
= 40 u + 200 u - 350 + 200 u
= 440 u - 350
440 u - 350 = 1410
440 u = 1410 + 350
440 u = 1760
1 u = 1760 ÷ 440 = 4
Difference between the value of $100-notes and $20-notes in the end
= 200 u - 40 u
= 160 u
= 160 x 4
= $640
Answer(s): $640