Which number is between 0.5 and 5/8 a.1/4 b.8/28 c.9/16 d.19/25

Try doing a number line :

0.505/8 

so then you need to convert 0.5 into a fraction so it looks like this :

0.5 is equal to 5/10 then you simplify 5/10 :

5 can go into 5 once so that's   1 
and  
5 can go into 10 twice so that's 2 

so you just simplify 5/10 into 1/2 
so your number line should now look something like this:

5/81/2 

then you can convert your fractions into percents 

A.1/4 is 25%
B.8/28 is 28.5%  (not sure)
C.9/16 is 56%     (not sure )
D. 19/25 is 76%

then you convert your numbers on your numbers line so that would be the fractions 5/8 and 1/2 

5/8 is 63%
1/2 is 50%

put them on a number line like this 

50%63% 

and your answers 
A.25%
B.28.5%
C.56%
D.76%

** Now you can easily scratch A. B. and D. because there either too high or too low  !!!

And the Answer is C. 56% or in the original question it would be C. 9/16