In an envelope, there were a total of 270 notes. 20% of them were $5-notes. The rest were $100-notes. Tim took out some $5-notes. As a result, the remaining $5-notes made up 10% of the notes left in the envelope. Find the total value of the $5-notes Tim took out from the envelope.
| |
$5 |
$100 |
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 $100-notes remains unchanged. Make the number of $100-notes the same. LCM of 4 and 9 is 36.
Total number of notes at first = 45 u
45 u = 270
1 u = 270 ÷ 45 = 6
Number of $5-notes that Tim took out from the envelope
= 9 u - 4 u
= 5 u
= 5 x 6
= 30
Total value of $5-notes taken out
= 30 x 5
= $150
Answer(s): $150
