In a box of notes, the number of $5, $10 and $20 are in ratio of 5 : 2 : 6.
35 of the $5-notes is taken out and another 11 $10-notes are added. The remaining notes are worth $1910. Find the difference between the value of $20-notes and $5-notes in the end.
| |
$5 |
$10 |
$20 |
| Before |
5 u |
2 u |
6 u |
| Change |
- 3 u |
+ 11 |
|
| After |
2 u |
2 u + 11 |
6 u |
| |
$5 |
$10 |
$20 |
Total |
| Number |
2 u |
2 u + 11 |
6 u |
|
| Value |
5 |
10 |
20 |
|
| Total value |
10 u |
20 u + 110 |
120 u |
1910 |
Total value of the notes
= 10 u + 20 u + 110 + 120 u
= 150 u + 110
150 u + 110 = 1910
150 u = 1910 - 110
150 u = 1800
1 u = 1800 ÷ 150 = 12
Difference between the value of $20-notes and $5-notes in the end
= 120 u - 10 u
= 110 u
= 110 x 12
= $1320
Answer(s): $1320
