Bunuel
In a set of 5 numbers, if the largest number is 3 more than the median, is the average value of the set greater than the median of the set?
(1) All the numbers are different. If the set is {-100, -10, 0, 1, 3}, then (median)=0>(average)=(some negative number) but if the set is {-2, -1, 0, 2, 3}, then (median)=0<(average)=(some positive number). Not sufficient.
(2) The median is 10 more than the smallest number in the set. The average will be maximized for the following set: {x-10, x, x, x+3, x+3} --> (average)=(x-10+x+x+ x+3+x+3)/5=x-4/5 and (median)=x --> x-4/5<x. Sufficient.
Answer: B.
I just thought that B tells us that it is not an evenly spaced set hence mean can not be equal to the median.
We dont really need to do know if it is greater or lesser than the mean in a DS question.
Correct me if wrong please
If the set is evenly spaced, mean = median - correct! But does that mean that if the set is NOT evenly spaced, mean cannot be equal to median? No.
e.g. 3, 4, 7, 9, 12 - mean = median = 7
So a non-evenly spaced set DOES NOT imply mean is not equal to median.
Secondly, are we sure that it will be either greater OR less only? What if we can take numbers such that both are possible for different numbers? So under the constraints, what if we can take numbers such that mean is greater in some cases and less in other cases? So we will need to analyse the statement a little further to find that mean MUST be less than median in all cases. How much less exactly is something we don't care about as long as we know that it must be less.