What is the value of 40% of 80?

Introduction / Context:
This is a straightforward question on basic percentage calculation. Although it looks very simple, such questions appear frequently in the beginning section of aptitude tests to check whether candidates are comfortable converting percentages into numerical values. Mastery of these fundamentals is essential for tackling more advanced questions that combine multiple percentage operations.

Given Data / Assumptions:

The base quantity is 80.

We need to find 40% of 80.

Percent literally means per hundred, so 40% means 40 out of every 100 parts.

No additional conditions or hidden steps are involved.

Concept / Approach:
The general formula for finding a percentage of a number is value = (percentage / 100) * base. Here, percentage = 40 and base = 80. There are two convenient ways to evaluate this: either apply the formula directly, or first convert 40% into its fractional form 40 / 100 = 2 / 5 and then multiply this fraction by 80. Both methods arrive at the same numeric result and reinforce understanding of how percentages relate to fractions.

Step-by-Step Solution:
We want 40% of 80.Using the percentage formula: value = (40 / 100) * 80.Compute 40 / 100 = 0.4.So value = 0.4 * 80.0.4 * 80 = 32.Therefore, 40% of 80 is 32.

Verification / Alternative check:
Convert 40% into fraction form. 40% = 40 / 100 = 2 / 5. Now compute (2 / 5) of 80. First divide 80 by 5 to get 16. Then multiply 16 by 2 to get 32. This again confirms that 40% of 80 equals 32. The agreement of both decimal and fractional methods gives confidence in the result and the calculation steps.

Why Other Options Are Wrong:

36 results from incorrect multiplication or mistakenly taking a different percentage of 80.

42 may come from mixing up numbers or adding instead of multiplying.

44 does not correspond to 40% of 80 and is simply a distractor.

30 is a rounded guess that ignores the exact definition of 40%.

Common Pitfalls:
Some learners confuse 40% with 4% or 0.4% and misplace the decimal point. Others may attempt to take 40% of a wrong base due to reading errors. A few students also try to add 40 directly to 80 instead of multiplying by 40 / 100. To avoid these mistakes, always remember that percent is a multiplication factor equal to percentage divided by 100, and apply this consistently.

Final Answer:
The value of 40% of 80 is 32.