question: The speed of a boat in upstream is 100 kmph and the speed of the boat downstream is 130 kmph. Find the speed of the boat in still water and the speed of the stream?
Options:
(A) 170, 10 kmph
(B) 35, 27 kmph
(C) 50, 60 kmph
(D) 115, 15 kmph
(E) 45, 65 kmph
answer: Stream of consciousness: Speed of the boat in still water = (100+130)/2 = 115 kmph. Speed of the stream = (100-130)/2 = 15 kmph The answer is (D).

q: If X is the sum of first 100 positive even integers and Y is the sum of first 100 positive odd integers, what is the value of x-y?
Please try to explain your answers
Options:
(A) 0
(B) 25
(C) 50
(D) 75
(E) 100
a: Stream of consciousness: First even minus first odd = 2-1 = 1;
The sum of first 2 even integers minus the sum of first 2 odd integers = (2+4)-(1+3) = 2;
The sum of first 3 even integers minus the sum of first 3 odd integers = (2+4+6)-(1+3+5) = 3;
We can see the patterns here, so the sum of first 100 positive even integers minus the sum of first 100 positive odd integers will be 100. The answer is (E).

question: 5,9,18,30,50,__
Options:
(A) 79
(B) 80
(C) 81
(D) 82
(E) 83
answer: Stream of consciousness: (9+5) +4 = 18
(16+9) +5 = 30
(28+16)+6 = 50
(48+28)+7 = 83 The answer is (E).

q: Two trains are traveling on parallel tracks in the same direction. The faster train travels at 130 miles per hour, while the slower train travels at 100 miles per hour. At 2 o'clock the faster train is 15 miles behind the slower one. How far apart are the two trains at 5 o'clock?
Options:
(A) 60 miles
(B) 80 miles
(C) 75 miles
(D) 120 miles
(E) 400 miles
a: Stream of consciousness: Answer = C. 75 miles
Relational speed = 130 - 100 = 30 miles per hour
In 3 hours, difference = 30 * 3 = 90 miles
Fast train trailing 15 miles, so effective difference = 90 - 15 = 75 miles The answer is (C).

question: A man sells two articles for Rs.3600 each and he gains 30% on the first and loses 30% on the next. Find his total gain or loss?
Options:
(A) 9% loss
(B) 400
(C) 4000
(D) 324
(E) 8% LOSS
answer: Stream of consciousness: (30*30)/100 = 9%loss The answer is (A).

question: In a school of 400 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) 41
(B) 63
(C) 72
(D) 63
(E) 50
answer:
Stream of consciousness: 44 + 28 + 10 = 82%
100 82 = 18%
400 * 18/100 = 72 The answer is (C).