Question

In a class of 120 students numbered 1 to 120 all even numbered

Answer 1

Answer:

Total = 120

Total who study Physics = 120/2 = 60

Total who study Chemistry = 120/5 = 24

Total who study Math = 120/7 = 17

Students who study all 3 subjects = LCM (2, 5, 7) = 70x = 1

Students who study only Physics and Chemistry = LCM (2,5) = 10x = 12 - 1(students who study all 3) = 11

Students who study only Physics and Math = LCM(2, 7) = 14x = 8 - 1 = 7

Students who study only Chemistry and Math = LCM(5, 7) = 35x = 3 - 1 = 2

Students who study only Physics = 60 - 11 - 7 - 1 = 41

Students who study only Chemistry = 24 - 11 - 2 - 1 = 10

Students who study only Math = 17 - 7 - 2 - 1 = 7

Total who study atleast one subject = 1 + 11 + 7 + 2 + 41 + 10 + 7 = 79

None = Total - Total who study atleast one subject = 120 - 79 = 41