question: The smallest number which when subtracted from the sum of squares of 11 and 13 gives a perfect square is
Options:
(A) 1
(B) 4
(C) 5
(D) 9
(E) 8
answer: Stream of consciousness: 11^2 + 13^2 = 121 + 169 = 290
290 - 1 = 289 = 17^2
1 must be subtracted to give a perfect square. The answer is (A).
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question: There are five same model cars parked in the same direction in parking. If 3 cars are red, 1 is black and 1 is green, in how many ways they can be arranged in the parking?
Options:
(A) 10 ways.
(B) 20 ways.
(C) 30 ways.
(D) 40 ways.
(E) 50 ways.
answer: Stream of consciousness: 5!/(3!*1!*1!) = (5*4*3*2*1)/(3*2*1) = 120/6 = 20 ways. The answer is (B).
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question: The average age of applicants for a new job is 30, with a standard deviation of 8. The hiring manager is only willing to accept applicants whose age is within one standard deviation of the average age. Assuming that all applicants' ages are integers and that the endpoints of the range are included, what is the maximum number of different ages of the applicants?
Options:
(A) 8
(B) 16
(C) 17
(D) 18
(E) 34
answer: Stream of consciousness: Minimum age = Average - 1 Standard deviation = 30 - 8 = 22
Maximum age = average + 1 Standard deviation = 30+ 8 = 38
Maximum number of different ages of the applicants = 38 - 22 + 1 = 17 The answer is (C).
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question: A train running at the speed of 60 km/hr crosses a pole in 12 sec. What is the length of the train?
Options:
(A) 120 m
(B) 200 m
(C) 324 m
(D) Cannot be determined
(E) None of these
answer:
Stream of consciousness: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 12 = 200 m The answer is (B).
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