fozzzy wrote:

If a is a positive whole number, is b also a positive whole number?

(1) The average (arithmetic mean) of a, (b + 2), and (a - 5) is a.

(2) The average (arithmetic mean) of a and b is NOT a positive whole number.

Shouldn't it be D? Can someone provide detailed analysis with examples. Thanks in advance!

whole numbers: 0 1 2 3.....

(1) The average (arithmetic mean) of a, (b + 2), and (a - 5) is a.

\((a+b+2+a-5)/3 = a\)

on solving \(b= a + 3\)

clearly b will be positive integer hence a whole number(as a is whole number)

HENCE SUFFICIENT

(2) The average (arithmetic mean) of a and b is NOT a positive whole number.

\((a+b)/2\) = this can be -ve / 0 / +ve fraction

when negative then it means that b is negative hence not a whole number

when 0 then b = -a so it can be whole number (when a=0) and not a whole number when a is positive

when fraction then b is either fraction or positive integer example : let a= 2 b = 3 avg = 2.5

hence insufficient

hence ans A

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