CAT Quantitative Aptitude: Percentage Concept

The concept of Percentages is an important topic for the CAT exam aspirants. The topics come in various forms in the CAT quantitative aptitude section as well as in the logical reasoning section. CAT exam aspirants must therefore prepare this topic thoroughly to get high percentile in the exam. “Per cent” as the word suggests means for every hundred. All questions from this concept are directed to find answers pertaining to percentage topics.

The objective of this article is to equip you will every possible concept and question which you might come across in the CAT and other MBA entrance exams. Read on to find out other details of this topic:

A percent is a ratio whose consequent is 100.

• ‘Percent’ comes from the Latin phrase per centum, which means per hundred
• % is used as the symbol for percent

When we say that ‘x is p% of y’ we mean that  x : y :: p : 100
For example, ‘My income is 20% of yours’ means that
         my income : your income :: 20 : 100

• As a fraction, x%=  , for example 75% =

Conversions

As ratios can be represented by fractions or numbers (decimals), so percent can also be represented by fractions or numbers (decimals). Several combinations of conversions are possible. The table below shows some important results.

NOTE: In the table above, a fraction is used to describe any real number written in the form a/b where b is not equal to 0. 

Percent Change

Whenever a change in a quantity is reported as a percentage, then it is given as a percentage of the old value. 

• If the new value is larger than the old value, then there is an increase in the value. In this case,

Example

My salary increased from Rs 12000 to Rs 15000 per month. What is the percentage change in my salary?

Solution

New salary = Rs 15000; Old salary = Rs 12000

Thus there is a 25% increase in my salary.

• If the new value is smaller than the old value, then there is a decrease in the value. In such a case,

Example

My salary was Rs 12000 last month and is Rs 10000 this month what is the percentage change in my salary?

Solution

As the new salary is smaller than the old salary, there is a decrease in my salary. Thus, in this case

Thus there is a 16.67% decrease in my salary.

For practising more exercises on other concepts of Quantitative Aptitude section, keep visiting MBA section of jagranjosh.com and get all the study material to prepare for the exam!

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MBA Quantitative Aptitude Section