The mean of a set of six numbers is 60. If the mean of the first five is 50, find the sixth number in the set.
-
A.
105 -
B.
100 -
C.
95 -
D.
110
Correct Answer: Option D
Explanation
Let the sum of the first five numbers and the sixth number be x and t respectively.
(frac{x + t}{6} = 60 implies x + t = 360)
(frac{x}{5} = 50 implies x = 250)
(therefore t = 360 – 250 = 110)