A shipment of 8 TV sets contains 5 black and white sets and 3 color sets. If 2 TV sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black and white set?
Options:
(A) 1/7
(B) 1/4
(C) 5/14
(D) 25/28
(E) 13/28
Answer and stream of consciousness: (D)
Stream of consciousness: 3/8 * 2/7 = 6/56
1-(6/56) = 50/56 = 25/28

Calculate the circumference of a circular field whose radius is 8 centimeters.
Options:
(A) 17 cm
(B) 18 cm
(C) 1 cm
(D) 16 cm
(E) 6 cm
Answer and stream of consciousness: (D)
Stream of consciousness: Circumference C is given by
C = 2r = 2*8 = 16 cm

A pipe can fill a cistern in 20 minutes whereas the cistern when fill can be emptied by a leak in 40 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17 minutes
(B) 87 minutes
(C) 40 minutes
(D) 27 minutes
(E) 11 minutes
Answer and stream of consciousness: (C)
Stream of consciousness: 1/20 - 1/40 = 1/40
40 minutes

In how many ways can you seat 4 people on a bench if one of them, Rohit, does not want to sit on the middle seat or at either end?
Options:
(A) 720
(B) 6
(C) 2880
(D) 5040
(E) 10080
Answer and stream of consciousness:
(B)
Stream of consciousness: Since Rohit does not want to sit on the middle seat or at either end (3 chairs), then he can choose 1 chairs to sit. The remaining 3 people can sit in 3! ways. Thus the # of arrangements is 1*3! = 6.