Post on 30-Dec-2015
Percentages and Percent Composition
Created by The North Carolina School of Science and Math. Copyright 2012. North Carolina Department of Public Instruction.
Percentages
Percent
Percentages
Examples?
30%0.5%120%
Number of People who Like This Team
Duke = 50 Carolina = 30NC State = 20 Other = 5
Percentages: Basic Equation
• A basic equation to help you solve problems with percentages:
Percentage = () x 100
Percentages: Types of Problems
What you Know What you are Trying to Find
Whole and Part PercentageWhole and Percentage
Part
Percentage and Part
Whole
Percentages: Examples
You are testing a airplane wing design in a wind tunnel. You complete 20 trials total. Only 15 of these trials were successful. What percentage of trials were successful?
Percentages: Examples
You are studying a specific metal alloy. You know that 10% of the alloy is made of steel. If you have a 50 gram sample of this material, how much of the material is steel?
Percentages: Examples
You have spent $120.00 on various materials for the prototype which you are designing. You know this is 80% of your design budget. What is your total budget?
Percent Composition
In Material Science…• Percent Composition is used to determine the
amount of each element in a compound
Why should Engineers care about this?