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

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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?

Choice (4)

a.

b.

c.

d.

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

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