The best way to answer this question is to set up the first sentence as a ratio of large bandages to total bandages. You would write 5 large bandages to 7 total bandages to 7 total bandages. Then you would make this equivalent to x number of large bandages to 60 total. It would look like this 5:7 = x:60. You could use cross products to multiply 60 by 5 to get 300. 7 times x also should equal 300. Unfortunately, this example will not leave us with a whole number of bandages, but 300/7 is a repeating decimal or a mixed number (42 6/7 large bandages).
A.
Store A has sold the most wristbands
Answer: 
<u>Step-by-step explanation:</u>
Given that the number is x,
10% increase will give us a new number of:
110/100*x
=1.1x
10% decrease will give us a new number of:
90/100*1.1x
=0.99x
This implies the new number is less than the original number
