Rationale: {Total} = {finance} + {marketing} - {both} + {neither}
100 = 25 + 52 - {both} + 40
{both} = 17%.
The answer: (D)
Question: Walking across campus, a student interviewed a group of students. 25% of the students took a finance class last semester, 52% took a marketing class last semester, and 40% took neither a finance nor a marketing class last semester. What percent of the students in the group took both a finance and a marketing class?
Options:
(A) 60%
(B) 50%
(C) 25%
(D) 17%
(E) 10%
Reasoning: (25/100) * 40 (4/5) * 25
10 - 20 = 10
Ans: (A)
Question: How much is 25% of 40 is greater than 4/5 of 25?
Options:
(A) 10
(B) 776
(C) 66
(D) 12
(E) 99
Rationale: Sum of the ages of the group having 4 persons and average 40 = 4x40 = 160
Sum of the ages of the group having 5 persons and average 38 = 5x38 = 190
Age of the new person added to the group = 190-160 = 30
The answer: (C)
Question: If we need to change the average age of a group containing 4 persons from 40 to 38 by adding a person. What should be the age of the person newly added to the group?
Options:
(A) 20
(B) 25
(C) 30
(D) 38
(E) 40
Reasoning: 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
Ans: (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) 1/9
(B) 1/6
(C) 1/5
(D) 1/0
(E) 1/1
Rationale: Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 360 + 140 = 500 m
Required time = 500 * 2/25 = 40 sec
The answer: (A)
Question: A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40
(B) 99
(C) 77
(D) 66
(E) 32
Rationale: Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 510 + 140 = 650 m
Required time = 650 * 2/25 = 52 sec
The answer: (B)
Question: A train 510 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40
(B) 52
(C) 26
(D) 21
(E) 14