q: Find a a prime number the options below.
Options:
(A) 78
(B) 80
(C) 81
(D) 82
(E) 83
a: Stream of consciousness: Clearly, 83 is a prime number. The answer is (E).

question: A owner of a mart earns an income of Re 1 on the first day of his business. On every subsequent day, he earns an income which is just double of that made on the previous day. On the 10th day of business, he earns an income of:
Options:
(A) 18
(B) 21
(C) 22
(D) 20
(E) 30
answer: Stream of consciousness: 2nd day he earns = 2(2 1)
3rd day he earns = 2(3 1)
On 10th day he earns 2(10 -1) = 18 rupees The answer is (A).

q: Using all the letters of the word "THURSDAY", how many different words can be formed?
Options:
(A) 8!
(B) 1
(C) 7
(D) 6
(E) 5
a: Stream of consciousness: Total number of letters = 8
Using these letters the number of 8 letters words formed is 8P8 = 4. The answer is (A).

question: A man rows his boat 105 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 7 kmph
(C) 12 kmph
(D) 8 kmph
(E) 1 kmph
answer: Stream of consciousness: Speed downstream = d/t = 105/(2 1/2) = 42 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (42 - 18)/2 = 12 kmph The answer is (C).

q: In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much?
Look at this series: 88, 3, 80, 12, __, 21 ... What number is missing?
Options:
(A) 72
(B) 78
(C) 68
(D) 30
(E) 70
a: Stream of consciousness: A
72
This is an alternating addition and subtraction series. In the first pattern, 8 is subtracted from each number to arrive at the next. In the second, 9 is added to each number to arrive at the next. The answer is (A).

q: Every day, Fred takes the train to travel from his work back to Alkmaar, his place of residence. Usually, he arrives at the station of Alkmaar at six o'clock, and exactly at that moment, his wife picks him up by car. Yesterday evening, Fred took an earlier train, without informing his wife, and therefore he already was at the station of Alkmaar at five o'clock. He decided to walk part of the way to meet his wife. When he met the car with his wife, he drove home with her. In this way, they were home ten minutes earlier than normal. Fred's wife always drives the entire way between home and station at the same constant speed.How long did Fred walk yesterday evening?
Options:
(A) 55
(B) 45
(C) 58
(D) 65
(E) 59
a:
Stream of consciousness: Fred's wife needed to drive ten minutes less than usual, which is five minutes less in the direction of the station and five minutes less back home. Therefore, Fred met his wife at five minutes to six. He had walked already since five o'clock, so he walked 55 minutes in total. The answer is (A).