While solving the GMAT CLub Quant Set 17 I came across a question stated below -
Set consists of positive numbers. If -1 is added as an element to set , which of the following is impossible ?
a. The mean will decrease but median will not change.
b. The median will decrease but mean will not change.
c.The range will increase but median will not change.
d. The range will increase but mean will decrease.
e. The standard deviation will increase but mean will decrease.
The correct ans is b as mean will always decrease if we add a negative no. but i was wondering in what case median will remain unchanged as some of the options specify. Can someone think of some examples.