Is the average (arithmetic mean) of a and b greater than 30?

Question

Is the average (arithmetic mean) of a and b greater than 30?
 
(1) a is a positive number.
(2) b is greater than 60.

DavidTutorexamPAL · Answer

To find the average of two numbers we need to know their sum.
We'll see whether the statements give us this information - a Logical approach.

(1) does not give us the sum of a and b.
Insufficient.

(2) does not give us the sum of a and b (as a could be negative).
Insufficient.

Combined: Now we know that the sum of a and b must be greater than 60 so their average must be greater than 30.
Enough information!
(C) is our answer.

preetamsaha · Answer

Is the average (arithmetic mean) of a and b greater than 30?

(1) a is a positive number.
no info about b  insufficient  
(2) b is greater than 60.
no info about a   insufficient

from (1) and (2) 
say,b= 60.000000000000000001 (taking smallest value as possible as can )
a= 1 ( smallest positive integer )

so, avg of a and b must be greater than 30
since,30 =   now, we are increasing both the values of a and b . so, avg must be greater than 30.  sufficient

correct answer c

Is the average (arithmetic mean) of a and b greater than 30?

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