Question 42408
If you have multiple choice problems I always work the problems by eliminating wrong answers. 

You should automatically be able to eliminate b. You should know that 2/5 is not equal to 5/2. 

You should also be able to automatically eliminate A and D. Both of those numbers have a whole number of 2 attached to them. 

You should know that 2/5 will never be bigger than 1. If you only have 2/5 then you definitely don't have 5/5, which would equal 1, so you definitely don't have 2. 

That leaves answer choice B. 
You can show that 2/5 = 0.4 in one of two ways:
           Calculator (if you are allowed to use one): Divide the top 
            number by the bottom number. 2/5 = 0.4
          If you can't use a calculator. Then change 2/5 to a number out of 100.
                      2/5 = 40/100  
              40/100 = 40%  = 0.4 or 0.40 
Hope this helps.