A die has two faces each with number 1,three faces each with number 2 and one face with number 3.If die is rolled once,determine P(1 or 3)

Question

$\begin{array}{1 1}(A)\;\large\frac{1}{2}\\(B)\;\large\frac{1}{4}\\(C)\;\large\frac{1}{8}\\(D)\;\large\frac{1}{6}\end{array} $

Answer 1

Toolbox:

• Required probability =$\large\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$

Step 1:

Given A die is rolled

$\therefore$ Total number of outcomes n(S)=6

The die has 2 faces with number 1

The die has 3 faces with number 2

The die has 1 face with number 3

Step 2:

Let E be the event of getting a number 1 or 3

$\therefore n(E)=2+1=3$

$\therefore$ Required probability =$\large\frac{n(E)}{n(S)}$

$\Rightarrow \large\frac{3}{6}$

$\Rightarrow \large\frac{1}{2}$

Hence (A) is the correct answer.