If a, b, c are consecutive positive integers and a<b<c, which of the following must be true?
I. c-b=1
II. abc is an even integer
III. (a+b+c)/3 is an integer	Choices.
A) I, II & III	B) II	C) I and II	D) II and III	E) I
1. c-b=1 --&gt; a, b, c are consequitive positive integers and a&lt;b&lt;c then c=b+1 --&gt; c-b=1. So this statement is always true;   2. abc is an even integer --&gt; out of any 3 consecutive integers at least one must be even thus abc=even. So this statement is also always true;   3. (a+b+c)/3 is an integer --&gt; the sum of odd number of consecutive integers is ALWAYS divisible by that odd number. So this statement is also always true. Or: (a+b+c)/3=(a+a+1+a+2)/3=(3a+3)/3=a+1=integer.   I, II &amp; IIInswer: I, II &amp; III.
<result>A</result>
If a, b, c are consecutive positive integers and a<b<c, which of the following must be true?
I. c-b=1
II. abc is an even integer
III. (a+b+c)/3 is an integer