Question

If the average (arithmetic mean) of four different numbers is 30, how many of the numbers are greater than 30 ?

Answer 1

Maximum 3 numbers. Minimum 1 number.

Explanation:

Well, let us look at the case when 3 numbers are greater than 30. Let us take numbers as 1, 2, 3 and 114 and find their mean which is (1+2+3+114)/4=30.

Now let us look at the case in which 2 numbers greater than 30. Let us take numbers 28, 29, 31 and 32 and find their mean which is (28+29+31+32)/4=30.

Now let us look at the case in which 1 number greater than 30. Let us take numbers 27, 28, 29 and 36 and find their mean which is (27+28+29+36)/4=30.

So it can be concluded that maximum 3 numbers and minimum 1 number are greater than 30.