Using the Percent Equation
General Explanation
In this lesson we will practice solving problems involving percent. Here
are some examples of the problems we will learn to solve:
What is 8% of 200? 2 is what percent of 135? 16 is 5% of what amount?All of these problems can be solved using the percent equation. The PERCENT EQUATION can be expressed as follows: PERCENT (as a decimal) x BASE = AMOUNTWhenever we solve problems using the percent equation, we must identify the PERCENT, the BASE, and the AMOUNT in the problem. The percent part is indicated by the % sign or the word "percent". The base part usually follows the word "of". The amount is the part that is related to the base by the percent. Sample Problem 1
What is 30% of 82?
Solution
We are given the PERCENT (30%) and the BASE (82). We are asked
to find the AMOUNT.
Let's use the percent equation to find the amount. PERCENT (as a decimal) x BASE = AMOUNT 0.30 x 82 = AMOUNT AMOUNT = 24.6Our final answer is 24.6. Sample Problem 2
90 is what percent of 360?
Solution
PERCENT is the unknown value. 360 follows the word "of", and is the BASE. 90 must be the AMOUNT.
Let's use the variable "n" to represent percent as a decimal number, and solve for "n" using the percent equation: PERCENT (as a decimal) x BASE = AMOUNT n x 360 = 90 n = 90/360 n = 0.25We have found the value of n in decimal form. To convert it to a percent move the decimal two places to the right. PERCENT = 25% |