In a pouch of notes, the number of $5, $10 and $20 are in ratio of 5 : 4 : 1.
45 of the $5-notes and 10 $10-notes are taken out. The remaining notes are worth $355. Find the difference between the value of $20-notes and $5-notes in the end.
|
$5 |
$10 |
$20 |
Before |
5 u |
4 u |
1 u |
Change |
- 4 u |
- 10 |
|
After |
1 u |
4 u - 10 |
1 u |
|
$5 |
$10 |
$20 |
Total |
Number |
1 u |
4 u - 10 |
1 u |
|
Value |
5 |
10 |
20 |
|
Total value |
5 u |
40 u - 100 |
20 u |
355 |
Total value of the notes
= 5 u + 40 u - 100 + 20 u
= 65 u - 100
65 u - 100 = 355
65 u = 355 + 100
65 u = 455
1 u = 455 ÷ 65 = 7
Difference between the value of $20-notes and $5-notes in the end
= 20 u - 5 u
= 15 u
= 15 x 7
= $105
Answer(s): $105