In an envelope, there were a total of 270 notes. 30% of them were $1-notes. The rest were $5-notes. Howard took out some $1-notes. As a result, the remaining $1-notes made up 25% of the notes left in the envelope. Find the total value of the $1-notes Howard took out from the envelope.
| |
$1 |
$5 |
Total |
| Before |
3x3 =
9 u |
7x3 =
21 u |
10x3 =
30 u |
| Change |
- ? |
|
|
| After |
1x7 =
7 u |
3x7 =
21 u |
4x7 =
28 u |
30% =
30100 =
310
25% =
25100 =
14
The number of $5-notes remains unchanged. Make the number of $5-notes the same. LCM of 7 and 3 is 21.
Total number of notes at first = 30 u
30 u = 270
1 u = 270 ÷ 30 = 9
Number of $1-notes that Howard took out from the envelope
= 9 u - 7 u
= 2 u
= 2 x 9
= 18
Total value of $1-notes taken out
= 18 x 1
= $18
Answer(s): $18
