during a math class, each of 24 students tossed three coins once. based on your answer to part B, how many students would you expect to get a result of 3 heads or 3 tails?

The probability of getting a result of HHH or TTT is 2/8 = 1/4. Then among 24 students there would be 24/4 = 6 who got this result (it is the most probable result, actually the number of students who get either HHH or TTT may be diffferent).