Question

Celina surveyed 60 students at her schools and found that 0.75 of students she surveyed said their favorite class is math. Another 35% of the students she surveyed reported that their favorite class is science. How many students in the survey prefer math over science?

Answer 1

0,75⇔75% (m)
35% (s)
75%+35%=110%
110%-100%=10% (m+s)
75%-10%=65% (only m)
60-100%
(?)-65%
65*60:100=39 (stud.)

Answer 2

0.75 of 60 = 45 students and 35% of 60 =21 students ,so it means there are 60-21=39 students with only maths ,45-39=6 students have both maths and science ,60-45=15 students with only science