Records show that 5% of all college students are foreign students who also smoke. it is also known that 50% of all foreign college students smoke. what percent of the students at this university are foreign?

10% Simplest way to solve this problem is realizing that if 50% of all foreign students smoke, then that also means that 50% of all foreign students don't smoke (100% - 50% = 50%). So for every smoking foreign student you see, there's a non-smoking foreign student. So just double the number of smoking foreign students to get the total number foreign students. So 5% * 2 = 10%