q: Find the invalid no.from the following series 13, 18, 25, 30, 37, 40
Options:
(A) 23
(B) 26
(C) 40
(D) 42
(E) 49
a: Stream of consciousness: The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong. The answer is (C).

question: In marathon Sam was faster than Jack. Denise beat Jim but lost to Jack. Who is the winner?
Options:
(A) Sam
(B) Jack
(C) Denise
(D) Jim
(E) none
answer: Stream of consciousness: Denise beat Jim
Jack beat Jim
Sam beat Jack
So Sam is the winner The answer is (A).

q: Which of the following is not divisible by 3?
Options:
(A) 10394
(B) 15363
(C) 29340
(D) 30753
(E) 41715
a: Stream of consciousness: Divisibility rule of 3: The sum of the digits of the number should be divisible by 3
Option A: 10394, Sum = 17. Not divisible by 3. Hence the number 10394 is also not divisible by 3
Option B: 15363, Sum = 18, Divisible by 3
Option C: 29340, Sum = 18, Divisible by 3
Option D: 30753, Sum = 18, Divisible by 3
Option E: 41715, Sum = 18, Divisible by 3 The answer is (E).

question: An design manager has 10patterns of chairs & 7patterns of tables. In how many ways can he make a pair of table & chair?
Options:
(A) 70
(B) 40
(C) 80
(D) 90
(E) 100
answer: Stream of consciousness: He has has ten patterns of chairs and eight patterns of tables
Hence, A chair can be arranged in 10 ways and
A table can be arranged in 7 ways
Hence one chair and one table can be arranged in 10 x 7 ways = 70 ways The answer is (A).

q: The average marks of a Suresh in 10 papers are 80. If the highest and the lowest scores are not considered, the average is 81. If his highest score is 92, find the lowest?
Options:
(A) 55
(B) 60
(C) 62
(D) 52
(E) Cannot be determined
a: Stream of consciousness: Total marks of 10 papers = 80 x 10 = 800
Total marks of 8 papers = 81 x 8 = 648
Total marks of two papers = (800 - 648) = 152
If highest total is 92, then the lowest total is
(152 - 92) = 60. The answer is (B).

q: A and B can do a work in 10 days and 15 days respectively. A starts the work and B joins him after 5 days. In how many days can they complete the remaining work?
Options:
(A) 6 days
(B) 2 days
(C) 8 days
(D) 4 days
(E) 3 days
a:
Stream of consciousness: Work done by A in 5 days = 5/10 = 1/2
Remaining work = 1/2
Work done by both A and B in one day = 1/10 + 1/15 = 5/30 = 1/6
Remaining work = 1/2 * 6/1 = 3 days. The answer is (E).