question: A can do a piece of work in 12 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 18
(B) 77
(C) 66
(D) 55
(E) 12
answer: Stream of consciousness: 8/12 + 6/x = 1
X = 18 days The answer is (A).

q: A boy runs 200 metres in 60 seconds. What is his speed ?
Options:
(A) 12 km/hr
(B) 24 km/hr
(C) 13 km/hr
(D) 14 km/hr
(E) 16 km/hr
a: Stream of consciousness: 200/60 * 18/5 = 12 km/hr The answer is (A).

question: There are different 15 circles. What is the number of the greatest possible points with which the circles intersect?
Options:
(A) 390
(B) 100
(C) 110
(D) 180
(E) 210
answer: Stream of consciousness: Maximum points of intersection between n different circles = n*(n - 1) = 15*14 = 210 The answer is (E).

q: How many seconds will a train 200 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 22 sec
(B) 35 sec
(C) 25 sec
(D) 18 sec
(E) 17 sec
a: Stream of consciousness: D = 200 + 150 = 350
S = 36 * 5/18 = 10 mps
T = 350/10 = 35 sec The answer is (B).

question: Two pipes A and B can fill a tank in 36 hours and 45 hours respectively. If both the pipes are opened simultaneously, how much time will be taken to fill the tank?
Options:
(A) 20 hrs
(B) 22 hrs
(C) 23 hrs
(D) 24 hrs
(E) 21 hrs
answer: Stream of consciousness: 1/( 1/36 +1/45) = 180/9 = 20 hrs The answer is (A).

question: Three years ago, the average age of a family of 5 members was 17. A baby having been born, the average age of the family is the same today. What is the age of the child?
Options:
(A) 3
(B) 2
(C) 4
(D) 1
(E) 5
answer:
Stream of consciousness: Present age of 5 members = 5 x 17 + 3 x 5 = 100 years
Also, present ages of 5 members + Age of the baby = 6 x 17 = 102 years
Age of the baby = 102 100 = 2 years. The answer is (B).