In an envelope, there were a total of 90 notes. 40% of them were $1-notes. The rest were $10-notes. Julian 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 Julian took out from the envelope.
|
$1 |
$10 |
Total |
Before |
2x3 = 6 u |
3x3 = 9 u |
5x3 = 15 u |
Change |
- ? |
|
|
After |
1x1 = 1 u |
9x1 = 9 u |
10x1 = 10 u |
40% =
40100 =
25
10% =
10100 =
110
The number of $10-notes remains unchanged. Make the number of $10-notes the same. LCM of 3 and 9 is 9.
Total number of notes at first = 15 u
15 u = 90
1 u = 90 ÷ 15 = 6
Number of $1-notes that Julian took out from the envelope
= 6 u - 1 u
= 5 u
= 5 x 6
= 30
Total value of $1-notes taken out
= 30 x 1
= $30
Answer(s): $30