I have come to the conclusion that I must ask for advice on question 9 page 35 of number properties book, which reads as follows:
If x, y and z are prime numbers and x<y<z, what is the value of x?
(I) xy is even
(II) xz is even
Now, the book says that both statements are sufficient, however I challenge that statement 1 is sufficient on its own, because:
x=1 and y=2 yields xy=1*2=2 ->. even number
x=2 and y=3 yields xy=2*3=6 -> even number
Since x can be both 1 and 2 (both are prime numbers, respect x<y and xy=even), this statement should be insufficient
IMHO, the unique sufficient statement is II and the answer to this question should be B, and not D as the book suggest.
I would greatly appreciate if you could help me out on this one
Thanks,