An engineer has 200 resistors that he keeps in one box. Resistors are colored to help their identification, and in this box there are 30 white resistors, 50 black resistors, 80 red resistors and 40 green resistors.
(a) If he chooses one resistor from this box without looking what is the
probability that the resistor is either black or white ?
If he chooses two resistors from this box without looking:
(b) what is the probability that both the resistors are green ?
(c) what is the probability that one resistor is red and the other resistor is white ?
(d) what is the probability that at most one of the resistors is green ?