q: A train 250 m long running at 72 kmph crosses a platform in 20 sec. What is the length of the platform?
Options:
(A) 150m
(B) 200m
(C) 250m
(D) 270m
(E) 300 m
a: Stream of consciousness: D = 72 * 5/18 = 20 = 400 â€“ 250 = 150m The answer is (A).


question: Find the remainder when 6^23 is divided by 5 ?
Options:
(A) 3
(B) 2
(C) 1
(D) 0
(E) 4
answer: Stream of consciousness: 6^23 = 6^(4*5+3) = 6^(20) * 6^3 last 3 digits = 216
216/5 remainder = 1 The answer is (C).


q: The average length of the sides of triangle ABC is 12. What is the perimeter of triangle ABC?
Options:
(A) 4
(B) 6
(C) 12
(D) 24
(E) 36
a: Stream of consciousness: (average) = (perimeter)/3;
12 = (perimeter)/3;
(perimeter) = 36. The answer is (E).


question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 7 kmph
(B) 6 kmph
(C) 5 kmph
(D) 8 kmph
(E) 2 kmph
answer: Stream of consciousness: Speed downstream = d/t = 85/(2 1/2) = 34 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (34 - 18)/2 = 8 kmph The answer is (D).


q: A 28 cm long wire is to be cut into two pieces so that one piece will be 2/5th of the other, how many centimeters will the shorter piece be?
Options:
(A) 12
(B) 8
(C) 88
(D) 77
(E) 14
a: Stream of consciousness: 1: 2/5 = 5: 2
2/7 * 28 = 8 The answer is (B).


q: The average of 10 numbers is calculated as 5. It is discovered later on that while calculating the average, one number namely 36 was wrongly read as 26. The correct average is?
Options:
(A) 2
(B) 3
(C) 4
(D) 5
(E) 6
a:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: 10 * 5 + 36 – 26 = 60/10 = 6 The answer is (E).