In a pouch of notes, the number of $2, $5 and $20 are in ratio of 7 : 3 : 6.
17 of the $2-notes is taken out and another 9 $5-notes are added. The remaining notes are worth $1221. Find the difference between the value of $20-notes and $2-notes in the end.
| |
$2 |
$5 |
$20 |
| Before |
7 u |
3 u |
6 u |
| Change |
- 1 u |
+ 9 |
|
| After |
6 u |
3 u + 9 |
6 u |
| |
$2 |
$5 |
$20 |
Total |
| Number |
6 u |
3 u + 9 |
6 u |
|
| Value |
2 |
5 |
20 |
|
| Total value |
12 u |
15 u + 45 |
120 u |
1221 |
Total value of the notes
= 12 u + 15 u + 45 + 120 u
= 147 u + 45
147 u + 45 = 1221
147 u = 1221 - 45
147 u = 1176
1 u = 1176 ÷ 147 = 8
Difference between the value of $20-notes and $2-notes in the end
= 120 u - 12 u
= 108 u
= 108 x 8
= $864
Answer(s): $864
