GMAT数学一道
Q10:
A set of numbers has the property that for any number t in the set,t + 2 is in the set.If –1 is in the set,which of the following must also be in the set?
I-3
II1
III5
A.I only
B.II only
C.I and II only
D.II and III only
E.I,II,and III