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 3 days?
Options:
(A) 1/9
(B) 1/7
(C) 1/6
(D) 1/2
(E) 1/1
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 3 days = 3 (1/18) = 1/6. 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) 45 Years
(B) 46 Years
(C) 49 Years
(D) 52 Years
(E) 54 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 (C).

q: If Rs.7500 are borrowed at C.I at the rate of 4% per annum, then after 2 years the amount to be paid is?
Options:
(A) 1227
(B) 2088
(C) 26788
(D) 8112
(E) 1871
a: Stream of consciousness: A = 7500(26/25)2 = 8112 The answer is (D).

question: A shipment of 8 TV sets contains 1 black and white sets and 7 color sets. If 2 TV sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black and white set?
Options:
(A) 1/7
(B) 1/4
(C) 5/14
(D) 11/28
(E) 13/28
answer: Stream of consciousness: 7/8 * 6/7 = 3/4
1-(3/4) = 1/4 The answer is (B).

q: In a photography exhibition, some photographs were taken by Octavia the photographer, and some photographs were framed by Jack the framer. Jack had framed 24 photographs taken by Octavia, and 12 photographs taken by other photographers. If 36 of the photographs in the exhibition were taken by Octavia, how many photographs were either framed by Jack or taken by Octavia?
Options:
(A) 36
(B) 48
(C) 72
(D) 96
(E) 108
a: Stream of consciousness: The number of photographs either framed by Jack or taken by Octavia = {Jack} + {Octavia} - {overlap} = 36 + 36 - 24 = 48 ({overlap} is green box). The answer is (B).

q: Rs.500 amounts to Rs.620 in 2 years at simple interest. If the interest is increased by 2%, it would amount to how much?
Options:
(A) 120
(B) 25
(C) 614
(D) 530
(E) 210
a:
Stream of consciousness: (500*3*2)/100 = 30
500+ 30 = 530 The answer is (D).