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binomial distrbution

Hi every one could you help me please?
I really stuk in this questiin.

In a particular area 30% of men and 20% of womaen are underweight. Four men and three women work in an office.

g)Find the probability that2 underweight people in the office?

You can find this question in AQA As level math book page 381.

Reply 1

RedGiant

Well you know the population size, and the probabilities of either case being true. So you can set up a random variable that follows the binomial distribution, and calculate the probability of the variable being 2, assuming that the events (selecting a person) are random, independent, and you only have a constant number of trials.