In an envelope, there were a total of 100 notes. 40% of them were $2-notes. The rest were $1-notes. Sam took out some $2-notes. As a result, the remaining $2-notes made up 20% of the notes left in the envelope. Find the total value of the $2-notes Sam took out from the envelope.
| |
$2 |
$1 |
Total |
| Before |
2x4 =
8 u |
3x4 =
12 u |
5x4 =
20 u |
| Change |
- ? |
|
|
| After |
1x3 =
3 u |
4x3 =
12 u |
5x3 =
15 u |
40% =
40100 =
25
20% =
20100 =
15
The number of $1-notes remains unchanged. Make the number of $1-notes the same. LCM of 3 and 4 is 12.
Total number of notes at first = 20 u
20 u = 100
1 u = 100 ÷ 20 = 5
Number of $2-notes that Sam took out from the envelope
= 8 u - 3 u
= 5 u
= 5 x 5
= 25
Total value of $2-notes taken out
= 25 x 2
= $50
Answer(s): $50
