The mean of a set of n numbers is 180, if 54 is added to the set of numbers the new mean is 159. Find n

Answer 1

totalbefore=n*180
total after=(n+1)159

but total after is total before+54

total before=n*180
total before+54=(n+1)159

or n*180=(n+1)159 -54
solve for n
n*180-159n=159-54
n=105/21=you do it.

Answer 2

55