In an envelope, there were a total of 80 notes. 70% of them were $100-notes. The rest were $10-notes. Zane took out some $100-notes. As a result, the remaining $100-notes made up 20% of the notes left in the envelope. Find the total value of the $100-notes Zane took out from the envelope.
| |
$100 |
$10 |
Total |
| Before |
7x4 =
28 u |
3x4 =
12 u |
10x4 =
40 u |
| Change |
- ? |
|
|
| After |
1x3 =
3 u |
4x3 =
12 u |
5x3 =
15 u |
70% =
70100 =
710
20% =
20100 =
15
The number of $10-notes remains unchanged. Make the number of $10-notes the same. LCM of 3 and 4 is 12.
Total number of notes at first = 40 u
40 u = 80
1 u = 80 ÷ 40 = 2
Number of $100-notes that Zane took out from the envelope
= 28 u - 3 u
= 25 u
= 25 x 2
= 50
Total value of $100-notes taken out
= 50 x 100
= $5000
Answer(s): $5000
