I go with C

stat 1 insuff : (1) x-y=1

could be : x=2 and y=1 ; 1/2! + 1/1! = 1/Q ; Q = 2/3

could also be : x=5 and y=4 ; 1/5! + 1/4! = 1/Q ; 1/120 + 1/24 = 1/Q

6/120 = 1/Q ; Q = 20

stat 2 insuff : (2) y is a nonprime even number ( =even >2)

could be : x=3 and y=4 ; 1/3! + 1/4! = 1/Q ; 1/6 + 1/24 = 1/Q ; Q = 5/24

could be : x= and y=4 ; 1/5! + 1/4! = 1/Q ; 1/120 + 1/24 = 1/Q

6/120 = 1/Q ; Q = 20

stat 1+2 suff

x=7 and y=6 ; 1/7! + 1/6! = 1/Q ; 8/5040 = 1/Q ; Q = 630

x=5 and y=4 ; 1/5! + 1/4! = 1/Q ; 1/120 + 1/24 = 1/Q

6/120 = 1/Q ; Q = 20

I don't have the pattern and the algebra to prove it, I just did 2 tries but it seems correct

In addition to MA I would add that normally neither X nor Y should be equal 1 because in the question it is written X hour

S and Y hour

S Some Verbal in the Quant part