Question

Edgar rolls two six-sided number cubes. What is the probability that he rollsan odd number on the first cube and a 4 on the second cube? Use thediagram of the sample space to help you.A. 3/6 = 1/8O A. 36OB. 36=O C. 11/2236OD. 36=14.

Answer 1

Since Edgar needs to roll a 4 on the second cube, the sample space gets reduced to the set shown below

$\begin{gathered} roll\text{ a 4 on the second cube} \\ \Rightarrow\lbrace(1,4),(2,4),(3,4),(4,4),(5,4),(6,4)\rbrace \end{gathered}$

Then, from the set above identify the ordered pairs such that their first number is odd (1,3,5,7,9,...). Thus, the set that satisfies both conditions is

$\Rightarrow\lbrace(1,4),(3,4),(5,4)\rbrace$

Therefore, out of 36 possible outcomes, only 3 satisfy the given condition; thus, the probability of such an event is

$P(odd\text{ number first, 4 second})=\frac{3}{36}=\frac{1}{12}$

The answer is option C.