__Introduction to Data Sufficiency__
Data sufficiency
questions consist of questions and two statements. These statements contain data
or information. Questions are based on any topic which we have already studied
in quantitative aptitude viz , Numbers, Averages , Percentages, Mensuration,
Algebra and reasoning topics like blood relations , puzzles etc.

Data sufficiency
questions are not only difficult but confusing also. Data sufficiency questions
require deeper knowledge in the subject area.Test takers generally get confuse
with the given information.

In data sufficiency
questions, we have to decide whether the data given in the statements labeled as
1 or 2 are sufficient to solve the given problem , There are 5 possible answer

Option A : If
stgatement 1 itself is sufficient to answer the question, but statement 2
itself is not

Option B : If
statement 2 itself is sufficient to answer the questions, but statement 1 itself
is not

Option C : If
statement 1 and 2 together are sufficient to answer the question, even though neither
statement by itself is not sufficient

Option D : If
either statement itself is sufficient to answer the question

Option E : Statements
(1) and (2) TOGETHER are NOT sufficient to answer the question asked, and
additional data specific to the problem are needed.

In data sufficiency
questions, to answer the questions, students don’t actually have to calculate
the values or answers. Students only have to determine whether the data given
in the statements are sufficient to find the answer for the given question.

**There are different kinds of data sufficiency questions:**

1.
For exams like IIM-CAT , there are only
four options

2.
For exams like GMAT , options are five

3.
Sometimes above given options may be
jumbled

4.
One or two options may be new type , while
remaining are same as above options

5.
There may be three or 4 statements follow a
questions

**How to solve Data Sufficiency Questions:**

**Tips to solve the questions based on data sufficiency:**

1.
The most important is understanding the
options. In CAT exams, students may have data sufficiency questions with 4
options and in GMAT options are fixed .In some other competitive exams options
in data sufficiency question vary.

2.
Read the questions carefully. Means , the
parent questions that is asked

3.
First check the statement 1 .Look at the statement 1 and the
information given in that. See whether information given in statement 1 is
sufficient to answer the question. When you see statement 1, ignore the
information given in statement 2

4.
Check the statement 2. Look at the
information given in the statement 2 . Most important that when information
given in statement 2 is considered, just forget the information given in statement
1. See whether the information given in statement 2 only is sufficient to
answer the question.

5.
When the statement 1 and 2 are individually
not enough to answer the question, use the information given in the both the
statements.

.

2. Number Theory - Data Sufficiency Problems

3. Data Sufficiency Questions on Percentages