In an envelope, there were a total of 135 notes. 20% of them were $10-notes. The rest were $1-notes. Julian took out some $10-notes. As a result, the remaining $10-notes made up 10% of the notes left in the envelope. Find the total value of the $10-notes Julian took out from the envelope.
|
$10 |
$1 |
Total |
Before |
1x9 = 9 u |
4x9 = 36 u |
5x9 = 45 u |
Change |
- ? |
|
|
After |
1x4 = 4 u |
9x4 = 36 u |
10x4 = 40 u |
20% =
20100 =
15
10% =
10100 =
110
The number of $1-notes remains unchanged. Make the number of $1-notes the same. LCM of 4 and 9 is 36.
Total number of notes at first = 45 u
45 u = 135
1 u = 135 ÷ 45 = 3
Number of $10-notes that Julian took out from the envelope
= 9 u - 4 u
= 5 u
= 5 x 3
= 15
Total value of $10-notes taken out
= 15 x 10
= $150
Answer(s): $150