q: In f is a positive integer smaller than 200 and (14f)/60 is an integer, then f has how many different positive prime factors?
Options:
(A) 2
(B) 3
(C) 5
(D) 6
(E) 8
a: Stream of consciousness: 7f/30 tells us that f is a factor of 30, which has 2, 3, and 5 as its prime factors. Each of them is distinct. Moreover, all multiples of 30 less than 200 can be derived by multiplying these prime factors alone. Thus, number of different prime factors is 3. The answer is (B).

question: A train 250 m long running at 72 kmph crosses a platform in 25 sec. What is the length of the platform?
Options:
(A) 150m
(B) 200m
(C) 250m
(D) 270m
(E) 300 m
answer: Stream of consciousness: D = 72 * 5/18 = 25 = 500 250 = 250m The answer is (C).

q: The floor of a rectangular room is 19 m long and 12 m wide. The room is surrounded by a veranda of width 2 m on all its sides. The area of the veranda is :
Options:
(A) 144 m2
(B) 140 m2
(C) 108 m2
(D) 158 m2
(E) None of these
a: Stream of consciousness: Area of the outer rectangle = 23 16 = 368 m2
Area of the inner rectangle = 19 12 = 228 m2
Required area = (368 228) = 140 m2 The answer is (B).

question: In a certain animal population, for each of the first 3 months of life, the probability that an animal will die during that month is 1/10. For a group of 600 newborn members of the population, approximately how many would be expected to survive the first 3 months of life?
Options:
(A) 438
(B) 446
(C) 452
(D) 462
(E) 470
answer: Stream of consciousness: Number of newborns that can die in first month = 1/10 *600 = 60
Survived = 540
Number of newborns that can die in second month = 1/10 * 540 = 54
Survived = 486
Number of newborns that can die in third month = 1/10 * 486 = 48
Survived = 438 The answer is (A).

q: What is the units digit of the expression 14^716^4?
Options:
(A) 0
(B) 3
(C) 8
(D) 6
(E) 4
a: Stream of consciousness: I think answer on this one should be C too. Since we know that 14^7>16^4, as Will said one should always check if the number is positive. The answer is (C).

q: A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job ?
Options:
(A) 19
(B) 15
(C) 16
(D) 17
(E) 18
a:
Stream of consciousness: Ratio of time taken by A & B = 160:100 = 8:5 Suppose B alone takes x days to do the job. Then, 8:5::12:x = > 8x = 5*12 = > x = 15 days. The answer is (B).