If a couple has two children, what is the approximate percentage chance that both are girls?

What is the mode in the following dataset representing ages of first sexual encounter: 16, 17, 18, 17, 19, 20, 17?

If the population of a town grows at a rate of 2% per year, approximately how many years will it take for the population to double, assuming the growth is primarily due to births?

If 1 in 100 people have a certain trait, what percentage of the population does *not* have that trait?

What is the median in the following dataset representing the number of sexual partners: 1, 2, 2, 3, 5, 8, 10?

If the average age of marriage increases by 1 year every decade, how much will it increase in 5 decades?

If a survey shows that 60 out of 200 people prefer option A, what percentage prefer option A?

Which of these numbers is considered a prime number?

If the probability of one event occurring is 0.2, what is the probability of it *not* occurring?

What is the range in the following dataset representing condom usage per week: 0, 1, 1, 2, 3, 5, 7?