Choosing a squad

What this combinatorics selection question tests

This is a straightforward combinatorics problem that appears frequently in quant interview screening. It tests whether you can correctly apply the combination formula to count the number of ways to select distinct subsets from two independent groups.

The key insight is recognizing that the selection of computer science students is independent of the selection of mathematics students, so you need to count the valid selections from each group separately and then combine them. Candidates should be comfortable with binomial notation, understand when order matters (it doesn't here), and arrive at the final count cleanly.

• Combination formula and binomial coefficients
• Independence of selection across groups
• Multiplication principle for independent choices