A question in the standardized test is:
The average of $n$ numbers is $a$. If $x$ is subtracted from each number the average will be
a) $(ax)/n\quad$ b) $(an)/x\quad$ c) $an-x\quad$ d) $n-x\quad$ e) $a-x$
The answer to this is e) $a-x$.
Could anyone please help me figure how the author got this answer ??