Q: If M is the least positive integer that is divisible by every integer from 4 to 12 inclusive, then M/11 is =
Options:
(A) 40320
(B) 27720
(C) 20160
(D) 6720
(E) 2520
A: OK... Stream of consciousness: The integer should be divisible by: 4, 5, 6, 7, 8, 9, 10, 11 and 12, that is 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 3*2^2. The least common multiple of these integers is the product of 11, 7, 5, 3^2 and 2^3. Then, M/11 is (11 * 7 * 5 * 3^2 * 2^3)/11 = 7*5*9*8 = 2520.
The answer is (E).

Q: 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 200 newborn members of the population, approximately how many would be expected to survive the first 3 months of life?
Options:
(A) 140
(B) 146
(C) 152
(D) 162
(E) 170
A: OK... Stream of consciousness: Number of newborns that can die in first month = 1/10 * 200 = 20
Survived = 180
Number of newborns that can die in second month = 1/10 * 180 = 18
Survived = 162
Number of newborns that can die in third month = 1/10 * 162 = 16
Survived = 146
The answer is (B).

Q: The average age of A, B and C is 25 years. If the average age of A and C is 29 years, what is the age of B in years ?
Options:
(A) 17
(B) 35
(C) 20
(D) 32
(E) 21
A: OK... Stream of consciousness: Age of B = Age of (A + B + C) Age of (A + C) = 25 3 29 2 = 75 58 = 17 years
The answer is (A).

Q: What will come in place of the x in the following Number series? 612, 207, 72, 27, 12, x
Options:
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10
A:
OK... Stream of consciousness: 612
612 / 3 + 3 = 207
207 / 3 + 3 = 72
72 / 3 + 3 = 27
27 / 3 + 3 = 12
12 / 3 + 3 = 7
The answer is (B).