In a pouch of notes, the number of $10, $20 and $50 are in ratio of 5 : 2 : 2.
15 of the $10-notes is taken out and another 13 $20-notes are added. The remaining notes are worth $800. Find the difference between the value of $50-notes and $10-notes in the end.
| |
$10 |
$20 |
$50 |
| Before |
5 u |
2 u |
2 u |
| Change |
- 1 u |
+ 13 |
|
| After |
4 u |
2 u + 13 |
2 u |
| |
$10 |
$20 |
$50 |
Total |
| Number |
4 u |
2 u + 13 |
2 u |
|
| Value |
10 |
20 |
50 |
|
| Total value |
40 u |
40 u + 260 |
100 u |
800 |
Total value of the notes
= 40 u + 40 u + 260 + 100 u
= 180 u + 260
180 u + 260 = 800
180 u = 800 - 260
180 u = 540
1 u = 540 ÷ 180 = 3
Difference between the value of $50-notes and $10-notes in the end
= 100 u - 40 u
= 60 u
= 60 x 3
= $180
Answer(s): $180
