Which question can be answered by finding 3 1/2÷1/4 A. You have 3 1/2 meters of ribbon and use 1/4 meter. How much ribbon is remaining?
B. How much is 1/4 of a 3/1/2-meter long piece of ribbon?
C. How many 1/4-meter long pieces of ribbon are needed to have a total of 3 1/2 meters of ribbon?

Choice C.

How many 1/4-meter long pieces of ribbon are needed to have a total of 3 1/2 meters of ribbon.

Explanation:

Let's consider a similar problem without the fractions.

Let's say you want to know how many 2 meter lengths of ribbon you can cut from an overall length of 24 meters. That would be 24 ÷ 2 = 12 pieces total.

So we divide the two values (large ÷ small)

The same idea applies to this problem as well. The larger amount (3 & 1/2 meters) is what we cut up, and each slice is 1/4 of a meter. To find the number of pieces, we would compute 3 1/2÷1/4

Note: it might help to convert the mixed number 3 & 1/2 to the improper fraction 7/2

1/800 is the right answer