Reasoning: Average speed = 2xy/(x+y) = (2*15*10)/25 = 12Kmph
Ans: (C)
Question: A person travels at a speed of 10 mph from one city to another. However while returning as there was not much traffic. He came with a speed of 15mph. what is his average speed?
Options:
(A) 10Kmph
(B) 11Kmph
(C) 12Kmph
(D) 13Kmph
(E) 14Kmph
Rationale: There are altogether three arrangements, which are we can select two members each from team A and B, each from team A and C, and each from team B and C. For each arrangement, there are altogether 64 possibilities (8*8) since each team has 8 players. So there are a total of 192 possibilities (64*3). I hope this method is easier for you to understand.
The answer: (C)
Question: There are 3 teams each with 8 basket players. How many combinations are there if we were to pick 2 players from the 3 teams such that no team was picked twice?
Options:
(A) 50
(B) 23
(C) 192
(D) 28
(E) 45
Reasoning: No of ways = 10+ 15 = 25
Ans: (E)
Question: There are 10 female and 15 male in a work place. In how many ways can a person can be selected?
Options:
(A) 20
(B) 15
(C) 18
(D) 40
(E) 25
Rationale: Sum of the ages of the students = 3915 = 585
New average = 15 years 3 months = 15 + 1414 year
Sum of the ages of students and teacher = 4015141514 = 40614614 = 610
Teacher age = 610 585 = 25 years.
The answer: (B)
Question: The average age of a class of 39 students is 15 years. If the age of the teacher be included, then the average increases by 3 months .Find the age of the teacher.
Options:
(A) 22
(B) 25
(C) 8
(D) 27
(E) 19
Reasoning: The length of cloth painted by one woman in one day = 48 / 4 2 = 6 m
No. of days required to paint 36 m cloth by 6 women = 36/ 6 6 = 1 day.
Ans: (C)
Question: If 4 women can color 48 m long cloth in 2 days, then 6 women can color 36 m long cloth in
Options:
(A) 2 days
(B) 3 days
(C) 1 day
(D) 4 days
(E) 5 days
Reasoning: D = 72 * 5/18 = 15 = 300 250 = 50m
Ans: (A)
Question: A train 250 m long running at 72 kmph crosses a platform in 15 sec. What is the length of the platform?
Options:
(A) 50m
(B) 200m
(C) 250m
(D) 270m
(E) 300 m