Chapter 6.7, Problem 5E

To determine

To find: the probability of the event of rolling a number less than 5.

Answer to Problem 5E

The probability of rolling a number less than 5 is $\frac{\text{2}}{\text{3}}$ .

Explanation of Solution

Given information :

A number cube is rolled and the favourable outcome is a number greater than 5.

Calculation :

Total number of possible outcomes in rolling a number cube is 6 i.e. 1, 2, 3, 4, 5, and 6.

Also

Total number of outcomes that is greater than 5 is 4that is 1, 2, 3, and 4 so, total number of favourable outcomes is 4.

Now,

  $\begin{array}{l}P\left(\text{Rolling Prime Number}\right)=\frac{\text{Number of favouarable outcome}}{\text{Number of possible outcome}}\\ P\left(\text{Rolling Prime Number}\right)=\frac{\text{4}}{\text{6}}\\ P\left(\text{Rolling Prime Number}\right)=\frac{\text{2}}{\text{3}}\end{array}$

Hence,

The probability of rolling a number less than 5is $\frac{\text{2}}{\text{3}}$ .