In a box of notes, the number of $2, $5 and $10 are in ratio of 5 : 5 : 2.
15 of the $2-notes is taken out and another 2 $5-notes are added. The remaining notes are worth $169. Find the difference between the value of $10-notes and $2-notes in the end.
|
$2 |
$5 |
$10 |
Before |
5 u |
5 u |
2 u |
Change |
- 1 u |
+ 2 |
|
After |
4 u |
5 u + 2 |
2 u |
|
$2 |
$5 |
$10 |
Total |
Number |
4 u |
5 u + 2 |
2 u |
|
Value |
2 |
5 |
10 |
|
Total value |
8 u |
25 u + 10 |
20 u |
169 |
Total value of the notes
= 8 u + 25 u + 10 + 20 u
= 53 u + 10
53 u + 10 = 169
53 u = 169 - 10
53 u = 159
1 u = 159 ÷ 53 = 3
Difference between the value of $10-notes and $2-notes in the end
= 20 u - 8 u
= 12 u
= 12 x 3
= $36
Answer(s): $36