In an envelope, there were a total of 280 notes. 75% of them were $50-notes. The rest were $1-notes. Vincent took out some $50-notes. As a result, the remaining $50-notes made up 30% of the notes left in the envelope. Find the total value of the $50-notes Vincent took out from the envelope.
|
$50 |
$1 |
Total |
Before |
3x7 = 21 u |
1x7 = 7 u |
4x7 = 28 u |
Change |
- ? |
|
|
After |
3x1 = 3 u |
7x1 = 7 u |
10x1 = 10 u |
75% =
75100 =
34
30% =
30100 =
310
The number of $1-notes remains unchanged. Make the number of $1-notes the same. LCM of 1 and 7 is 7.
Total number of notes at first = 28 u
28 u = 280
1 u = 280 ÷ 28 = 10
Number of $50-notes that Vincent took out from the envelope
= 21 u - 3 u
= 18 u
= 18 x 10
= 180
Total value of $50-notes taken out
= 180 x 50
= $9000
Answer(s): $9000