In an envelope, there were a total of 280 notes. 70% of them were $5-notes. The rest were $100-notes. Ian took out some $5-notes. As a result, the remaining $5-notes made up 20% of the notes left in the envelope. Find the total value of the $5-notes Ian took out from the envelope.
| |
$5 |
$100 |
Total |
| Before |
7x4 =
28 u |
3x4 =
12 u |
10x4 =
40 u |
| Change |
- ? |
|
|
| After |
1x3 =
3 u |
4x3 =
12 u |
5x3 =
15 u |
70% =
70100 =
710
20% =
20100 =
15
The number of $100-notes remains unchanged. Make the number of $100-notes the same. LCM of 3 and 4 is 12.
Total number of notes at first = 40 u
40 u = 280
1 u = 280 ÷ 40 = 7
Number of $5-notes that Ian took out from the envelope
= 28 u - 3 u
= 25 u
= 25 x 7
= 175
Total value of $5-notes taken out
= 175 x 5
= $875
Answer(s): $875
