Answer:
18
Step-by-step explanation:
The expected value is the probability times the frequency.
3 = 1/6 × n
n = 18
Note: the use of the word "odds" is very misleading here. Odds are the ratio of number of successes to number of failures:
S / F
Probability is the ratio of number of successes to number of all outcomes:
S / (S + F)
So the probability of rolling a 5 is 1/6. The odds of rolling a 5 is 1/5.
Furthermore, the word "must" is also incorrect. The player didn't <em>have</em> to roll 18 times. They could have rolled three times and gotten a 5 each time. Or they could have rolled 100 times. 18 is simply the most <em>likely </em>number of rolls needed to get three 5's.
Assuming the +'s are actually x's 1/2 of 3 is 1.5 and 1.5 divided by 7 is 1.5/7.(answer is 1.5/7) hopefully I'm right.
Answer:
0.40951
Step-by-step explanation:
P(none in five years) = 1 - 0.1 = 0.9
P(at least one) = 1 - P(none in five years)
= 1 - 
= 1 - 0.59049
= 0.40951
So the probability of a hurricane hit at least once in the next 5 years is 0.40951
