I am in IT/210 and am having problems with the entire class. But what I am stuck on is as follows:

Question

Consider the following statement where X is an integer test score between 0 and 100.

input X
if (<0=X and X<49)
output = "you fail"

else if (50 <=X and X < 70)
output"your grade is" X
output"you did OK"

else if (70<=X and X <85)
output "your grade is" X
output"you did well"

else if (85<=X and X <100)
output "your grade is" X
output "you did great"

endif
output "how did you do?"

What will be printed of the input is 0?
What will be printed if the input is 100?
What will be printed if the input is 51?
What will be printed if user enters "Winding"?
Is this design robust? If so, explain why. If not, explain what you can do to make it robust.
How many levels of nesting are there in this design?
Give one set of values that will test the normal operation of this program segment.

Defend your choices.
Give a set of test values that will cause each of the branches to be executed.
Give a set of test values that the test abnormal operation of this program segment.

I'm not understanding how to do this. Can someone please help me? Is there a web site one can go to to get assistance with these types of problems?
Thank you