In a pouch of notes, the number of $2, $5 and $10 are in ratio of 3 : 3 : 2.
13 of the $2-notes and 2 $5-notes are taken out. The remaining notes are worth $68. Find the difference between the value of $10-notes and $2-notes in the end.
| |
$2 |
$5 |
$10 |
| Before |
3 u |
3 u |
2 u |
| Change |
- 1 u |
- 2 |
|
| After |
2 u |
3 u - 2 |
2 u |
| |
$2 |
$5 |
$10 |
Total |
| Number |
2 u |
3 u - 2 |
2 u |
|
| Value |
2 |
5 |
10 |
|
| Total value |
4 u |
15 u - 10 |
20 u |
68 |
Total value of the notes
= 4 u + 15 u - 10 + 20 u
= 39 u - 10
39 u - 10 = 68
39 u = 68 + 10
39 u = 78
1 u = 78 ÷ 39 = 2
Difference between the value of $10-notes and $2-notes in the end
= 20 u - 4 u
= 16 u
= 16 x 2
= $32
Answer(s): $32
