In a pouch of notes, the number of $10, $20 and $50 are in ratio of 5 : 1 : 4.
45 of the $10-notes and 2 $20-notes are taken out. The remaining notes are worth $1570. Find the difference between the value of $50-notes and $10-notes in the end.
| |
$10 |
$20 |
$50 |
| Before |
5 u |
1 u |
4 u |
| Change |
- 4 u |
- 2 |
|
| After |
1 u |
1 u - 2 |
4 u |
| |
$10 |
$20 |
$50 |
Total |
| Number |
1 u |
1 u - 2 |
4 u |
|
| Value |
10 |
20 |
50 |
|
| Total value |
10 u |
20 u - 40 |
200 u |
1570 |
Total value of the notes
= 10 u + 20 u - 40 + 200 u
= 230 u - 40
230 u - 40 = 1570
230 u = 1570 + 40
230 u = 1610
1 u = 1610 ÷ 230 = 7
Difference between the value of $50-notes and $10-notes in the end
= 200 u - 10 u
= 190 u
= 190 x 7
= $1330
Answer(s): $1330
