Rationale: 10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5
The answer: (C)
Question: 10 books are placed at random in a shelf. The probability that a pair of books will always be together is
Options:
(A) 1/6
(B) 1/9
(C) 1/5
(D) 1/6
(E) 1/3
Reasoning: 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
Ans: (D)
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) 4 kmph
(C) 4 kmph
(D) 8 kmph
(E) 5 kmph
Rationale: 10 men 120 acres 15 days
20 men ? 30 days
120 * 20/10 * 30/15
120 *2 * 2
120 * 4 = 480
The answer: (E)
Question: If 10 men can reap 120 acres of land in 15 days, how many acres of land can 20 men reap in 30 days?
Options:
(A) 120
(B) 240
(C) 360
(D) 1200
(E) 480
Reasoning: D = 120 + 150 = 270
S = 36 * 5/18 = 10 mps
T = 270/10 = 27 sec
Ans: (D)
Question: How many seconds will a train 120 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 17 sec
(B) 21 sec
(C) 25 sec
(D) 27 sec
(E) 29 sec
Rationale: Cost price of article = 48$
% of overhead cost = 10
Net profit = 12 $
We need to calculate % markup
Net profit as % of cost price = (12/48)*100 = 25%
Total markup should be = 25 + 10 = 35%
The answer: (C)
Question: The purchase price of an article is $48. In order to include 10% of cost for overhead and to provide $12 of net profit, the markup should be
Options:
(A) 15%
(B) 25%
(C) 35%
(D) 40%
(E) 45%
Rationale: Total number of votes polled = (6136 + 7636 + 11628) = 25400
So, Required percentage = 11628/25400 * 100 = 46%
The answer: (A)
Question: 3 candidates in an election and received 6136, 7636 and 11628 votes respectively. What % of the total votes did the winning candidate got in that election?
Options:
(A) 46%
(B) 49%
(C) 57%
(D) 59%
(E) 61%