Find closest fraction to another fraction

[KarlRixon]

I'm trying to teach myself maths and I'm stuck at this problem:

Homework Statement

Which of the following fractions is nearest to \frac{1}{2}?

You must show your working.

\frac{3}{5} \frac{7}{10} \frac{11}{20}

Homework Equations

The Attempt at a Solution

I know the answer is \frac{11}{20}, because it just is! What I don't know how to do is "show my working". I've tried searching for "find closest fraction to another fraction" but I can't seem to find the proper technique for calculating this. Any pointers will be gratefully received.

 

[Rajini]

Hi,
I guess you can show by dividing each fraction!
e.g., 3/5 =0.6 and compare the each fraction's result with 1/2=0.5

 

[KarlRixon]

That makes sense! Thanks.

 

[Dadface]

Alternatively put them all over the same common denominator.