In a box of notes, the number of $10, $50 and $100 are in ratio of 7 : 5 : 3.
17 of the $10-notes and 5 $50-notes are taken out. The remaining notes are worth $4020. Find the difference between the value of $100-notes and $10-notes in the end.
| |
$10 |
$50 |
$100 |
| Before |
7 u |
5 u |
3 u |
| Change |
- 1 u |
- 5 |
|
| After |
6 u |
5 u - 5 |
3 u |
| |
$10 |
$50 |
$100 |
Total |
| Number |
6 u |
5 u - 5 |
3 u |
|
| Value |
10 |
50 |
100 |
|
| Total value |
60 u |
250 u - 250 |
300 u |
4020 |
Total value of the notes
= 60 u + 250 u - 250 + 300 u
= 610 u - 250
610 u - 250 = 4020
610 u = 4020 + 250
610 u = 4270
1 u = 4270 ÷ 610 = 7
Difference between the value of $100-notes and $10-notes in the end
= 300 u - 60 u
= 240 u
= 240 x 7
= $1680
Answer(s): $1680
