Solving Data Sufficiency Questions

Data sufficiency is one of the few topics that can be found in both the reasoning and math sections. Data sufficiency is a common topic on the tests that the government gives in this country.

The biggest mistake people make when answering data sufficiency questions is that they guess instead of solving the questions, which causes them to lose points.

What is Data Sufficiency

The goal of Data Sufficiency is to see if the information given is enough to answer a question. Questions of this type are meant to see if the candidate can use the information given to come to a conclusion. Also, the data sufficiency test has more things to check on the candidate.

Types of Data Sufficiency

Let’s look at the different types of Data Sufficiency one at a time.

Blood Relation 

In this type of data sufficiency, you’ll be asked about the relationship between two people. You’ll need to find the statement(s) that give you enough information to figure out the relationship or the right answer.

Order & Ranking

In this type of data sufficiency, information will be given about the order of people or their ranking, and candidates will need to find the statement(s) in which the information is enough to find the right answer.

Direction & Distance 

In this type of data sufficiency, candidates will be given information about the direction of people or points, the distance travelled by a person, or the distance between two points. They will then have to find the statement(s) in which the information is enough to figure out the direction or distance between the two points.

Coding-Decoding 

In this type of data sufficiency, words or letters will be coded, and candidates will need to find the statement(s) in which data is enough to find the logic used to decide the code.

Seating Arrangement

In this type of data sufficiency, candidates will be given information about how people are arranged and will have to find the statement(s) in which the information is enough to find the right answer. There are two different ways to set up seats; in a straight line or in a circle. People will be arranged or seated in one or more rows in Linear Arrangement. In Circular Arrangement, people will be arranged or seated around a round table.

Floor Puzzle

In this type of data sufficiency, candidates will be given information about people who live on different floors of either the same building or a different building. They will then need to find the statement(s) in which the information is enough to find the right answer.

Scheduling

In this type of data sufficiency, candidates will be given information based on months, years, or dates, and they will have to decide if the information given in the statements is enough or not.

Data Sufficiency in Logical Reasoning Questions

How to Work It Out

Each of the questions below has a question and two statements below it that are numbered I and II. You have to decide if the statements give you enough information to answer the question. Read given paragraphs and give the answer:

(A) If the information in statement I alone is enough to answer the question, but the information in statement II alone is not enough,

(B) If the information in statement II alone is enough to answer the question, but the information in statement I alone is not enough.

(C) If the information in either statement I or II alone is enough to answer the question.

(D) If both statements I and II don’t give enough information to answer the question, and

(E) If you need the information in both statements I and II to answer the question.

1. What year did Rahul come into the world?

Statements:

Rahul is 25 years younger than his mother right now.

Rahul’s mother is 35 years older than his brother, who was born in 1964.

1. I alone is enough, but II alone is not enough.
2. II alone is enough, but I alone is not enough.
3. Either I or II are enough.
4. Neither I nor II are enough.
5. I and II are both enough.

Answer: Option E

Explanation:

We can tell from I and II that Rahul is 10 years older than his brother, who was born in 1964 because 35 – 25 = 10. In 1954, Rahul was born.

2. Question: What is the total weight of 10 poles if each one weighs the same?

Statements:

One-fourth of each pole’s weight is 5 kg.

The weight of three poles is 20 kilogrammes more than the weight of two poles.

1. I alone is enough, but II alone is not enough.
2. II alone is enough, but I alone is not enough.
3. Either I or II are enough.
4. Neither I nor II are enough.
5. I and II are both enough.

Choice C is right.

Explanation:

From I, we can figure out that each pole weighs (4×5) kg, which is 20 kg.

So, the weight of all 10 poles is equal to 20 x 10 kg, which is 200 kg.

We can tell from II that:

Each pole weighs 20 kg, which is the difference between the weights of three poles and two poles.

So, 10 poles weigh a total of 20 x 10 kg, or 200 kg.

Conclusion

In Data Sufficiency, the problems based on data sufficiency reasoning consist of a question followed by some statements that provide clues to answer the question. Candidates need not find the answer to the question. Candidates just need to check whether the given statement is sufficient to answer the question and accordingly choose the answer from the options provided.