In an envelope, there were a total of 320 notes. 30% of them were $5-notes. The rest were $50-notes. Ethan took out some $5-notes. As a result, the remaining $5-notes made up 20% of the notes left in the envelope. Find the total value of the $5-notes Ethan took out from the envelope.
| |
$5 |
$50 |
Total |
| Before |
3x4 =
12 u |
7x4 =
28 u |
10x4 =
40 u |
| Change |
- ? |
|
|
| After |
1x7 =
7 u |
4x7 =
28 u |
5x7 =
35 u |
30% =
30100 =
310
20% =
20100 =
15
The number of $50-notes remains unchanged. Make the number of $50-notes the same. LCM of 7 and 4 is 28.
Total number of notes at first = 40 u
40 u = 320
1 u = 320 ÷ 40 = 8
Number of $5-notes that Ethan took out from the envelope
= 12 u - 7 u
= 5 u
= 5 x 8
= 40
Total value of $5-notes taken out
= 40 x 5
= $200
Answer(s): $200
