Question

A spinner has 4 equal sections numbered 1 to 4. You spin it twice. Find the probability of the events.18. Spinning a 2 and then an even number.19. Spinning an odd number and then another odd number.

Answer 1

Let:

A = event of spinning a 2

B = event of spinning an even number

C = event of spinning an odd number

18. Spinning a 2 and then an even number:

$\begin{gathered} P(A)=\frac{1}{4} \\ P(B)=\frac{2}{4}=\frac{1}{2} \end{gathered}$

Since they are independent events:

$P(A\cap B)=\frac{1}{4}\cdot\frac{1}{2}=\frac{1}{8}=0.125$

As a percentage: 12.5%

19. Spinning an odd number and then another odd number:

$P(C)=\frac{2}{4}=\frac{1}{2}$

so:

Since they are independent events:

$P(C\cap C)=\frac{1}{2}\cdot\frac{1}{2}=\frac{1}{4}=0.25$

As a percentage: 25%