Question

What is the probability of rolling a 3 with a number cube that has the numbers 1, 2, 3, 4, 5, and 6 and then, tossing heads with a coin?

A. 1/12

B. 1/8

C. 1/2

D. 2/3

Answer 1

Since the possibility of possible outcome is independent for the two events, we can calculate the first one as 1 in 6, and the second one as 1 in 2. Multiply 1/6 and 1/2 the answer is 1/12.

Answer 2

There are 6different numbers on a cube and 3 is one of them so P(getting a 3) = 1/6
P(getting a head with the coin) = 1/2

These 2 events are independent so their probs are multiplied

So P(3 then head) = 1/6 8*1/2 -= 1/12