question: Which of the following is equal to (x+1)!/x!
Options:
(A) x-1
(B) 1+(1/x)
(C) x+1
(D) 1
(E) x
answer: Stream of consciousness: (x + 1)! = (x + 1) * x!
(x + 1)!/x! = x + 1 The answer is (C).

q: An archer is shooting arrows from various distances. She shoots at a target from 40 yards, 50 yards, and 60 yards. The probability that she hits within the bullseye from 40 yards is 4/5, the probability that she hits within the bullseye from 50 yards is 3/4, and the probability that she hits within the bullseye from 60 yards is 2/3. What is the probability that she hits the bullseye at least once in three shots, one from each distance listed.
Options:
(A) 39/40
(B) 49/50
(C) 59/60
(D) 9/10
(E) 14/15
a: Stream of consciousness: The probability that she hits the bullseye at least once = 1 - (the probability that she misses the bullseye every shot)
The probability that she misses every shot = (prob that she misses from 40 yards)*(prob that she misses from 50 yards)*(prob that she misses from 60 yards)
Prob that she misses from 40 yards = 1 - 4/5 = 1/5; Prob that she misses from 50 yards = 1 - 3/4 = 1/4; Prob that she misses from 60 yards = 1 - 2/3 = 1/3
Thus the probability that she misses all shots = (1/5)*(1/4)*(1/3) = 1/60
Thus the probability that she makes at least one shot = 1 - (1/60) = 59/60 The answer is (C).

question: The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 29 Years
(B) 32 Years
(C) 37 Years
(D) 49 Years
(E) 50 Years
answer: Stream of consciousness: Total age of students is 32X16 = 512 Years
Total age inclusive of teacher = 33X (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33X1) = 49 Years The answer is (D).

q: The compound ratio of 2/3, 6/7, 1/3 and 1/8 is given by?
Options:
(A) 1/56
(B) 1/42
(C) 1/40
(D) 1/41
(E) 1/47
a: Stream of consciousness: 2/3 * 6/7 * 1/3 * 1/8 = 1/42 The answer is (B).

question: Seven men can complete a work in 12 days. They started the work and after 5 days, two men left. In how many days will the work be completed by the remaining men?
Options:
(A) 5 days
(B) 6 days
(C) 9 days
(D) 10 days
(E) None of these
answer: Stream of consciousness: 7 x 12 men complete the work in 1 day
Therefore, 1 man's 1 day's work = 1/84
7 men's 5 days work = 5/12
Remaining work = 1- 5/12 = 7/12
5 men's 1 day's work = 5/84
5/84 work is don by them in 1 day
7/12 work is done by them in ((84/5) x (7/12)) = 49/5 days = 9 4/5 days The answer is (E).

question: Which is odd one
10, 25, 45, 54, 60, 75, 80
Options:
(A) 10
(B) 45
(C) 54
(D) 60
(E) 75
answer:
Stream of consciousness: All numbers except 54 is multiple of 5. The answer is (C).