Question

What is the probability that a number selected at random from 1, 2, 2, 3, 3, 3, 4, 4, 4, 4 will be their average?

• A. 0.5
• B. 0.2
• C. 0.3
• D. 1

Answer 1

The correct option is C 0.3

First thing is to get the average of the above numbers.
Average = $\frac{1+2+2+3+3+3+4+4+4+4}{10}$
= $\frac{30}{10}$=3
Number of times '3' occurs in the given numbers is '3'.
$\therefore$ required probability (of getting 3 as average) = $\frac{\text{No. of favorable outcomes}}{\text{total No. of outcomes}}=\frac{3}{10}=0.3$