Question

catherine has a 6 - sided number cube that is numbered from 1 through 6. she plans on rolling the number cube 60 times. about how many times should she expect to roll a number that is greater than 4?
10
15
20
40

Explanation:

Step1: Determine favorable outcomes

Numbers greater than 4 on a 6 - sided cube are 5 and 6. So there are 2 favorable outcomes out of 6 total outcomes.

Step2: Calculate probability

The probability $P$ of rolling a number greater than 4 is $P=\frac{2}{6}=\frac{1}{3}$.

Step3: Find expected number of rolls

She rolls the cube 60 times. The expected number of times $E$ of rolling a number greater than 4 is $E = 60\times\frac{1}{3}=20$.

Answer:

20