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 700 newborn members of the population, approximately how many would be expected to survive the first 3 months of life?
Options:
(A) 511
(B) 546
(C) 552
(D) 562
(E) 570
Answer and stream of consciousness: (A)
Stream of consciousness: Number of newborns that can die in first month = 1/10 * 700 = 70
Survived = 630
Number of newborns that can die in second month = 1/10 * 630 = 63
Survived = 567
Number of newborns that can die in third month = 1/10 * 567 = 56
Survived = 511


In what time a sum of money double itself at 3% per annum simple interest?
Options:
(A) 33 1/7%
(B) 33 1/3%
(C) 33 1/2%
(D) 33 7/3%
(E) 33 5/3%
Answer and stream of consciousness: (B)
Stream of consciousness: P = (P*3*R)/100
R = 33 1/3%


Ronald and Elan are working on an assignment. Ronald takes 6 hours to type 32 pages on a computer, while Elan takes 5 hours to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?
Options:
(A) 3 hours
(B) 6 hours
(C) 4 hours
(D) 8 hours
(E) 10 hours
Answer and stream of consciousness: (D)
Stream of consciousness: Number of pages typed by Ronald in one hour = 32/6 = 16/3
Number of pages typed by Elan in one hour = 40/5 = 8
Number of pages typed by both in one hour = ((16/3) + 8) = 40/3
Therefore, time taken by both to type 110 pages = 110 x 3/40 = 8 hours.


In the expression 51840/x^4, for which of the following values of x will the expression NOT be an integer?
Options:
(A) 1/2
(B) 1
(C) 2
(D) 3
(E) 5
Answer and stream of consciousness:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
(E)
Stream of consciousness: We can straightaway eliminate A & B, since the expression will always yields an integer for those values
Out of C, D, and E. Let us consider option E. 51840 has only one trailing zero and tens digit is not 5, so It has just one 5 in it. But for the expression to be an integer numerator should have 5^4.