A number cube has sides labeled 1 to 6.
Hannah rolls the number cube 18 times.
How many times can she expect to roll a
number less than 3?
A2 C6
B3 D8
The expected value is the number of rolls multiplied by the probability of each success on the roll (as success is the top face of the die is a 2 or a 1) and the probability of that success is 2/6 which reduces to 1/3
So the expected value in 18 rolls
= 18 x 1/3
the answer is 6 or C I had the same exact question and I got it right.
To find out how many times Hannah can expect to roll a number less than 3, we need to determine the probability of rolling a number less than 3 and then multiply it by the total number of rolls.
In this case, the number cube has sides labeled 1 to 6. We can see that the numbers less than 3 are 1 and 2, so there are 2 favorable outcomes.
To find the probability, we divide the number of favorable outcomes (2) by the total number of possible outcomes (6), which is the total number of sides on the cube:
Probability = (Number of favorable outcomes) / (Total number of possible outcomes)
Probability = 2 / 6
Probability = 1 / 3
Now, we multiply the probability by the total number of rolls (18) to find how many times Hannah can expect to roll a number less than 3:
Expected number of times = Probability * Total number of rolls
Expected number of times = (1/3) * 18
Expected number of times = 6
Therefore, Hannah can expect to roll a number less than 3 six times.