Topics in Problem Solving on the GMAT include:

1. Numbers and Exponents
2. Equations (Linear & Quadratic), Inequations, Absolute Value
3. Ratio, Proportion, Variation
4. Percentages, Profit and Loss
5. Time & Distance, Time & Work
6. Geometry & Mensuration
7. Functions & Graphs, Coordinate Geometry
8. Counting Methods - P & C
9. Sets & Venn Diagrams; Probability
10. Miscellaneous (Statistics; SI/CI; Mixtures; Basic Data Interpretation)

Some sample questions in Problem Solving are given below:

1. A company manufactures power switches. The first 1,000 power switches manufactured at a cost of $ 2,000 and subsequent power switches manufactured at a cost of $ x each. If it cost $ 8,160 to manufacture the first 5,000 pens, what is the value of x?
   (A) 1.54
   (B) 1.63
   (C) 1.65
   (D) 1.8
   (E) 1.95


2. A certain experiment was conducted in a lab under different temperatures and recorded the values as -285°, 0°, -127°, -85°, 4°, 200° and 23°. What is the median of these temperatures?
   (A) -127°
   (B) -85°
   (C) 0°
   (D) 23°
   (E) 200°

Though Indians do well in Problem solving, most of them struggle with Data Sufficiency as this is a new question type to most of them. In Problem Solving, we need to solve a given problem and find the answer. In Data Sufficiency (DS), there is no need to find the answer. We need to find if the given information is enough to solve a problem. Hence the approach for these questions should be different and lot of practice and coaching are required.

Each of the problems on data sufficiency below consists of a question and two statements, labelled (1) and (2), in which certain data is given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements plus your knowledge of mathematics and every-day facts (such as the number of days in January or the meaning of counterclockwise), you must indicate one of the following answer choices:

A) if statement (1) alone is sufficient and statement (2) alone is not sufficient to answer the question.
B) if statement (2) alone is sufficient and statement (1) alone is not sufficient to answer the question.
C) if statements (1) and (2) together are sufficient but neither statement alone is sufficient to answer the question.
D) if each statement alone is sufficient to answer the question.
E) if both the statements (1) and (2) together are not sufficient to answer the question and additional data specific to the problem is needed

1. What is the value of the non-positive integer n?
   (1) The average of the square of n and 'n' is 6.
   (2) n < 1


2. What is the probability of A/B if A and B are mutually exclusive events?
   (1) P(A) = 0.2 and P(B) = 0.5
   (2) P(A n B) = 0


3. Is (a + b) < (c + d)?
   (1) c and d are negative integers such that (a + b)3 - (c + d)3 = 0.
   (2) a and b are positive integers such that (a + b)2 - (c + d)2 = 0.