10th Class Mathematics Probability Question Bank MCQs - Probability

A number is selected at random from the numbers\[\text{2},\text{4},\text{4},\text{ 6},\text{6},\text{6},\text{ 8},\text{8},\text{8},\text{8}\]. The probability that the selected number is their average is:

A) \[\frac{1}{10}\]

B) \[\frac{3}{10}\]

C) \[\frac{7}{10}\]

D) \[\frac{9}{10}\]

Correct Answer: B

Solution :

[b] Total number of possible outcomes =10 Sum of the given numbers

\[=2+4+4+6+6+8+8+8+8=60\]

\[\therefore \] Average \[=\frac{\text{Sum of all the given numbers}}{\text{Total numbers}}=\frac{60}{10}=6\]

6 occurs 3 times.

So. favourable number of outcomes = 3

\[\therefore \] Required probability \[=\frac{3}{10}\]