q: Maximum no of unsuccessful attempts, a thief can do in order to break a number locking system of 4 digits.
Options:
(A) 9988
(B) 9999
(C) 9799
(D) 9685
(E) 6545
a: Stream of consciousness: From 0 to 9999 there are 10000 four digit numbers
So maximum number of unsuccessful attempts = 10000 - 1 = 9999 The answer is (B).

question: Find a a prime number from below options?
Options:
(A) 84
(B) 97
(C) 98
(D) 100
(E) 102
answer: Stream of consciousness: Clearly, 97 is a prime number. The answer is (B).

q: A class consists of 100 students, 25 of them are girls and 75 boys; 20 of them are rich and remaining poor; 40 of them are fair complexioned. The probability of selecting a fair complexioned rich girl is
Options:
(A) 1/50
(B) 1/59
(C) 1/56
(D) 1/54
(E) 1/53
a: Stream of consciousness: The probability of selecting girl is: 25/100 = 1/4
The probability of selecting rich is: 20/100 = 1/5
The probability of selecting fair complexioned is: 40/100 = 2/5
Three are independent;probability of rich and fair complexioned girl is:
(1/4) (1/5) (2/5) = 1/50 The answer is (A).

question: The average age of A, B and C is 25 years. If the average age of A and C is 29 years, what is the age of B in years ?
Options:
(A) 17
(B) 35
(C) 20
(D) 32
(E) 21
answer: Stream of consciousness: Age of B = Age of (A + B + C) Age of (A + C) = 25 3 29 2 = 75 58 = 17 years The answer is (A).

q: Pipes A and B can fill a cistern in 8 and 24 minutes respectively. They are opened an alternate minutes. Find how many minutes, the cistern shall be full?
Options:
(A) 12 min
(B) 6 min
(C) 4 min
(D) 8 min
(E) 10 min
a: Stream of consciousness: 1/8 + 1/24 = 1/6
6 * 2 = 12 The answer is (A).

q: Look at this series: 72, 76, 73, 77, 74, __, 75, ... What number should fill the blank?
Options:
(A) 70
(B) 71
(C) 75
(D) 78
(E) 74
a:
Stream of consciousness: There will be 2 series
1st: 72 73 74 75 76 (Increasing by 1)
2nd: 76 77 78 79 (Increasing by 1)
Final: 72 76 73 77 74 78 75 The answer is (D).