In a class of 100 students, 30 are computer science majors, 49 are mechaincal engineering majors, 13 are civil engineers and the rest are general engineering majors. Assume students only have one major.

If a student is chosen at random what is the probability they are:
a civil engineering major? 1 (Format: decimal 0.XX)
a civil enginering major or mechanical engineering major?
a general engineering major?
not a computer science major?
Suppose five students from the class are chosen at random what is the probability none are mechanical engineering majors?

2 answers

For the first one, 13% are Civil Engineers, but where do I go from there?
Probability is not a percentage. Change format to decimal.

Either-or probabilities are found by adding the individual probabilities.

General = (100-30-49-13)/100 = ?

Not computer = (100-30)/100 = ?

If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.

5 not mech = [(100-49)/100]^5 = ?