the answer is b i did the math it checks out
The amount of different ways possible can be shown by 7!=5040 Im pretty sure.
Answer: X is 0.4
Explanation: I typed 5/2 x a bunch of random numbers and decimals on a calculator until I tried 0.4 and when I typed 5/2 x 0.4 on the calculator it said 5/2 x 0.4 = 1.