In a pouch of notes, the number of $5, $10 and $20 are in ratio of 7 : 4 : 8.
47 of the $5-notes is taken out and another 6 $10-notes are added. The remaining notes are worth $1565. Find the difference between the value of $20-notes and $5-notes in the end.
| |
$5 |
$10 |
$20 |
| Before |
7 u |
4 u |
8 u |
| Change |
- 4 u |
+ 6 |
|
| After |
3 u |
4 u + 6 |
8 u |
| |
$5 |
$10 |
$20 |
Total |
| Number |
3 u |
4 u + 6 |
8 u |
|
| Value |
5 |
10 |
20 |
|
| Total value |
15 u |
40 u + 60 |
160 u |
1565 |
Total value of the notes
= 15 u + 40 u + 60 + 160 u
= 215 u + 60
215 u + 60 = 1565
215 u = 1565 - 60
215 u = 1505
1 u = 1505 ÷ 215 = 7
Difference between the value of $20-notes and $5-notes in the end
= 160 u - 15 u
= 145 u
= 145 x 7
= $1015
Answer(s): $1015
