Answer to Question #254590 in Statistics and Probability for liera

Question

A student has to take seven more courses before she can graduate. If none of the courses are prerequisites to others, how many groups of four courses can she select for the next semester?

Answer 1

Solution:

The order does not matter.

So, we use combination.

$$C(7,4)=\binom{7}{4}={7! \over 4!(7-4)!}=\dfrac{7.6.5}{3.2.1}=35$$

A student can select 35 groups of four courses.