P ercentage is the idea of expressing a fraction whose denominator is 100 to aid comparison. You could expect a couple of questions in the GMAT quant section testing concepts covered in this topic. One is expected to be adept at interchangeably expressing values as fractions, decimals and percents.

### Concepts Covered

Percentages, fractions are basic concepts that appear frequently as part of the GMAT Problem Solving section. Wizako's GMAT Math Lesson Book in this chapter covers the following concepts:

- The meaning of the term percent and the need for using percentages
- The relation between percents, fractions and decimals and the rules to convert from one form to another with illustrative examples
- Explanation of the percentage change in values along with illustrative examples
- 11 illustrative examples. 23 solved examples with detailed explanation and special mention of shortcuts wherever applicable
- 29 exercise problems with answer key and explanatory answers
- An objective type test with 40 GMAT level questions in the work book. Answer key and explanatory answers for all questions are provided

Here is a typical solved example from this chapter.

### Sample Question

In an examination a candidate who secured 20% of the maximum marks failed by 10 marks. Another candidate who secured 30% of the maximum marks got 20 marks more than the pass mark. What is the pass mark in this examination?

#### Explanatory Answer

Let the pass mark in the examination be P and the maximum marks be M.

Candidate 1 secured 20% of maximum marks, which was 10 marks less than pass mark.

i.e., 20% of M = P - 10 ... (1)

Candidate 2 secured 30% of maximum marks, which was 20 marks more than pass mark.

i.e., 30% of M = P + 20 ... (2)

Subtract equation (1) from equation (2): 10% of M = 30

If 10% of the maximum marks is 30, maximum marks, M = 300

The pass mark is obtained by substituting M = 300 in one of the two equations.

In equation (1): 20% of M = P - 10

20% of 300 = P - 10

60 = P - 10

Or P = 70. Pass mark, P = 70

### Chapterwise details of Wizako's Math Lesson Books

Math Lesson Book 1

1 | Linear Equations | Details |

2 | Quadratic Equations | Details |

3 | Set Theory | Details |

4 | Sequences & Series | Details |

5 | Number Properties & Theory | Details |

6 | Inequalities | Details |

7 | Functions |