q: Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 2 days?
Options:
(A) 2/5
(B) 1/6
(C) 1/4
(D) 1/9
(E) 2/6
a: Stream of consciousness: A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 2 days = 2 (1/18) = 1/9. The answer is (D).

question: From among the 36 students in a class, one leader and one class representative are to be appointed. In how many ways can this be done?
Options:
(A) 1360
(B) 1260
(C) 1060
(D) 1160
(E) 1460
answer: Stream of consciousness: There are 36 students and every one has equal chance of being selected as a leader. Hence, the leader can be appointed in 36 ways. When one person is appointed as leader, we are left with 35 students. Out of these 35 teachers, we can select one class representative. So, a class representative can be selected in 35 ways. Hence, the number of ways in which a leader and class representative can be selected = 36 x 35 = 1260 The answer is (B).

q: The average age of a family of 6 members is 28 years.If the age of the youngest member is 7 years,what was the average age of the family at the birth of the youngest member?
Options:
(A) 15
(B) 18
(C) 21
(D) 12
(E) 19
a: Stream of consciousness: Present age of total members = 6 X 28 = 168
7 yrs back their ages were = 6 x 7 = 42
Ages at the birth of youngest member = 168 - 42 = 126
Therefore, avg age at the birth of youngest member = 126/6 = 21. The answer is (C).

question: Two trains are moving at 85 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 5 25/31 sec
(B) 7 1/17 sec
(C) 7 2/2 sec
(D) 8 1/2 sec
(E) 7 1/9 sec
answer: Stream of consciousness: 70 + 85 = 155 * 5/18 = 775/18 mps
D = 150 + 100 = 250 m
T = 250 * 18/775 = 180/31 = 5 25/31 sec The answer is (A).

q: The speed of a boat in still water is 60kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 80,70 kmph
(B) 87,40 kmph
(C) 80,40 kmph
(D) 70,40 kmph
(E) 80,44 kmph
a: Stream of consciousness: Speed downstream = 60 + 20 = 80 kmph
Speed upstream = 60 - 20 = 40 kmph The answer is (C).

q: Eight people are planning to share equally the cost of a rental car. If one person withdraws from the arrangement and the others share equally the entire
rest of the car, then the share of each of the remaining persons increased by ?
Options:
(A) 1/9
(B) 1/8
(C) 1/7
(D) 7/8
(E) 8/7
a:
Stream of consciousness: When there are eight people, the share of each person is 1/8th the total cost The answer is (B).