In a pouch of notes, the number of $2, $10 and $100 are in ratio of 7 : 5 : 4.
27 of the $2-notes and 13 $10-notes are taken out. The remaining notes are worth $3550. Find the difference between the value of $100-notes and $2-notes in the end.
|
$2 |
$10 |
$100 |
Before |
7 u |
5 u |
4 u |
Change |
- 2 u |
- 13 |
|
After |
5 u |
5 u - 13 |
4 u |
|
$2 |
$10 |
$100 |
Total |
Number |
5 u |
5 u - 13 |
4 u |
|
Value |
2 |
10 |
100 |
|
Total value |
10 u |
50 u - 130 |
400 u |
3550 |
Total value of the notes
= 10 u + 50 u - 130 + 400 u
= 460 u - 130
460 u - 130 = 3550
460 u = 3550 + 130
460 u = 3680
1 u = 3680 ÷ 460 = 8
Difference between the value of $100-notes and $2-notes in the end
= 400 u - 10 u
= 390 u
= 390 x 8
= $3120
Answer(s): $3120