In a bag of notes, the number of $5, $20 and $50 are in ratio of 3 : 3 : 8.
13 of the $5-notes is taken out and another 4 $20-notes are added. The remaining notes are worth $2900. Find the difference between the value of $50-notes and $5-notes in the end.
| |
$5 |
$20 |
$50 |
| Before |
3 u |
3 u |
8 u |
| Change |
- 1 u |
+ 4 |
|
| After |
2 u |
3 u + 4 |
8 u |
| |
$5 |
$20 |
$50 |
Total |
| Number |
2 u |
3 u + 4 |
8 u |
|
| Value |
5 |
20 |
50 |
|
| Total value |
10 u |
60 u + 80 |
400 u |
2900 |
Total value of the notes
= 10 u + 60 u + 80 + 400 u
= 470 u + 80
470 u + 80 = 2900
470 u = 2900 - 80
470 u = 2820
1 u = 2820 ÷ 470 = 6
Difference between the value of $50-notes and $5-notes in the end
= 400 u - 10 u
= 390 u
= 390 x 6
= $2340
Answer(s): $2340
