In an envelope, there were a total of 300 notes. 70% of them were $1-notes. The rest were $100-notes. Archie took out some $1-notes. As a result, the remaining $1-notes made up 10% of the notes left in the envelope. Find the total value of the $1-notes Archie took out from the envelope.
| |
$1 |
$100 |
Total |
| Before |
7x3 =
21 u |
3x3 =
9 u |
10x3 =
30 u |
| Change |
- ? |
|
|
| After |
1x1 =
1 u |
9x1 =
9 u |
10x1 =
10 u |
70% =
70100 =
710
10% =
10100 =
110
The number of $100-notes remains unchanged. Make the number of $100-notes the same. LCM of 3 and 9 is 9.
Total number of notes at first = 30 u
30 u = 300
1 u = 300 ÷ 30 = 10
Number of $1-notes that Archie took out from the envelope
= 21 u - 1 u
= 20 u
= 20 x 10
= 200
Total value of $1-notes taken out
= 200 x 1
= $200
Answer(s): $200
