Aptitude [TCS Placement]: Sample Questions 117 - 119 of 174

Get unlimited access to the best preparation resource for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.

Question 117

Aptitude

Question

MCQ▾

100 students appeared for two examinations. 60 passed the first, 50 passed the second and 30 passed both. Find the probability that a student selected at random has failed in both the examinations?

Choices

Choice (4)

a.

b.

c.

d.

Answer

c.

Explanation

  • We know that,
  • Let A be number of students who passed in first exam.
  • Let B be number of students who passed in second exam.
  • We are asked to find the probability of student who failed in both the examinations.
  • So 80 passed in at least one of the exams.
  • So, 100 - 80 = 20 students are there who failed in both exams.
  • Probability of student who failed in both the exams

Question 118

Aptitude
Edit

Write in Short

Short Answer▾

A is 20 percent more efficient than B. If two persons can complete a piece of work in 60 days then in how many days A working alone can complete the work?

Explanation

A is 20 % more efficient than B.

Ratio of time taken by A and B is .

If B can do work in 6x days then A can do the same amount of work in 5x days.

So,

A can complete the work in 5x days, i.e.. days.

Question 119

Aptitude

Question

MCQ▾

Four people each roll a fair dice once. Find the probability that at least two people will roll the same number?

Choices

Choice (4)

a.

b.

c.

d.

Question does not provide sufficient data or is vague

Answer

c.

Explanation

  • First time probability of getting the same number will be .
  • Second time when the die is thrown probability of getting the same number will be
  • Third time when the die is thrown probability of getting the same number will be .
  • Fourth time when the die is thrown probability of getting the same number will be
  • We are asked to find the probability when at least two people will roll the same number.
  • The probability of at least two persons will roll the same number = 1 - None of them rolls the same number

Developed by: