Logical Reasoning Questions for Coding Interview

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These Logical Reasoning Questions are designed for Coding Interviews at Companies hiring for Software Development or Engineering roles (Full-time + Intern). These questions are frequently asked at Amazon, Microsoft and other companies. These are usually asked in the first round of Interview.

The questions are of Increasing Difficulty. Practice all questions.

Q1. Consider the following sequence: 10, 14, 12, 16, 14, 18, 16, 20, ...
What is the next number is the sequence?

The next number in the sequence is 18. If you notice the sequence carefully, you will see that it starts with 10 and every alternative number is generated by adding 4 or subtracting 2. To generate the number after 20, we need to subtract 2 from 20 which leads us to 18.

Q2. There are two statements:
a. Tomato is red in color;
b. No red-colored thing is cheap.
Conclusions:
1. Tomato is cheap;
2. Red-colored Tomato is not cheap.
Which conclusion is true?

Conclusion 2

Conclusion 1

Both conclusion 1 and 2

None

Conclusion 2 is right. Conclusion 1 is false because the first statement clarifies that all tomatoes are red and by statement 2, we know that no such tomato can be cheap.

Q3. If Cup is to Lip, then Bird is to?

Beak

Grass

Fish

Sky

If Cup is to Lip, then Bird is to Beak. Beak is the mouth of a Bird.

Q4. If Melt is to Liquid, then Freeze is to?

Solid

Vapor

Liquid

Condense

If something melts, it becomes liquid. Similarly, if something freezes, it will become a solid.

Q5. Which one is the odd one out?

Important

Trivial

Unimportant

Insignificant

Important is the odd one out. All 3 other words related to the opposite meaning of the word "important".

Q6. In 2021, you are 25 years old and your sister is 20 years old. In which year, will your age be double the age of your sister?

2006

2036

1990

2010

In 2006, your age was 10 years and your sister's age was 5 years so your age was double. It will not happen in future as the difference in age is 5 years.

Q7. What is 2 raised to the power 12

4096

1024

512

2¹² = 4096. This is a standard question to Programmers to check mental calculation ability. You need to know the powers to two up to 10 at least. The powers of 2 are: 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, ...

Q8. If you will take 10 days to code a solution in C++ and 30 days to code it in Rust, how much time will it take to code with Rust API with C++ backend?

40 days

10 days

20 days

30 days

If you need to code C++ backend, you are taking 10 days and then, to make Rust API, you need to define all class and function definitions and call the C++ code from within. Therefore, the time to code in Rust is added up. 10 days + 30 days = 40 days.

Q9. Which Shopkeeper takes your belongings and charge money to do so?

Barber

Garbage Collector

House Maid

Theif

Barber cuts your hair and keeps the cut hair. To do so, barber charges some money.

Q10. A boy and a doctor were fishing by the Pool. The boy is the doctor's son, but the doctor is not the boy's father. Who is the doctor?

Mother

Stranger

Kidnapper

Step-Father

The Doctor is the Mother of the boy. This makes the boy the son of the Doctor.

Q11. There are two statements:
1. There are 45 students in class.
2. 12 students scored less than Mark.
Which statements are needed to find the rank of Mark?

Both 1 and 2

Only 1

Only 2

Need 3rd statement

From the two statements, we know there are 45 - 12 - 1 = 32 students who scored more than Mark. So, rank of Mark is 33 (= 32 + 1). This problem checks your Data Sufficiency logic.

Q12. What is the essential part of a Book?

Paper

Knowledge

Education

Ink

A book is a collection of paper so paper is the essential part. This questions tests your logic to identify essential components and not over think.

Q13. What is the essential component to start coding?

Keyboard

Computer

Electricity

Editor

You can type using a keyboard and therefore, to start coding, you need a keyboard. The keyboard can be a virtual keyword, a mechanical keyboard for typewriter, a QWERTY keyboard for a computer and so on. This questions tests your logic to identify essential components and not over think.

Q14. Consider the following three statements:
1. John is older than Mark.
2. Selina is older than John.
3. Mark is older than Selina. First 2 statements are true, then statement 3 is:

False

True

Uncertain

Insufficient Information

The statement 3 is false. This question tests your logic to identify conflicting requirements in a project.

For the next 3 questions (Q15 to Q17), consider the following funding data:

Launch a new Search Engine: $5 Million
Setup a new office in New York: $3.5 Million
Create a new innovative game: $2 Million
Rewrite codebase in Rust: $1.5 Million
Launch a Education program with high schools: $1 Million
Renovation of site: $0.5 Million
Give bonus to all employees: $0.5 Million

Note: There are a total of $10 Million fund to be used.

Q15. The company decides to Launch a new search engine, setup a new office and give bonus to all employees, which is the only task that can be done?

Launch a Education program

Rewrite codebase in Rust

Renovation of site

Create a new innovative game

As only $1 Million is left, there is only option left to be done to fully utilize the funds.

Q16. If the company decides to invest the money at the rate of 15% and the cost of task increase by 6%, how many years should they wait to get all tasks done together?

4 years

6 years

1 year

9 years

Total cost of all tasks is $14 Million. For N years, 14 * (1.06)^N = 10 * (1.15)^N. Therefore, N is 4.128 years so the company needs to waits approximately 4 years.

Q17. There are 7 tasks. What is the maximum number of tasks that can be done using the current funds of $10 Million?

6 tasks can be funded. This includes all tasks except "Launch a new Search Engine" and this involves $9 Million with $1 Million left.

Q18. Consider the following statements: A > B, B ≥ C, C < D. Following are 2 conclusions:
1. A > C
2. A = C
Which statement is correct?

Conclusion 1 is true

Conclusion 2 is true

Both are true

None is true

Only Conclusion 1 is true.

With these questions at OpenGenus, you must have a good practice of Logical Reasoning Questions for Coding Interview. Enjoy.

Q1. Consider the following sequence: 10, 14, 12, 16, 14, 18, 16, 20, ...What is the next number is the sequence?

Q2. There are two statements:a. Tomato is red in color;b. No red-colored thing is cheap.Conclusions:1. Tomato is cheap;2. Red-colored Tomato is not cheap.Which conclusion is true?