According to a Wakefield Research survey of adult women...

According to a Wakefield Research survey of adult women, 50% of the women said that they had tried five of more diets in their lifetime. Suppose that this result is true for the current population of adult women. A random sample of 13 adult women is selected. Use the binomial probabilities table or technology to find the probability of the number of women in this sample of 13 who had tried 5 or more diets in their lifetime is 
a) at most 7
b) 5 to 8
c) at least 7