Solving Proportion Problems

Tags: Ap Us History Document Based EssayEffects Of Moving To Another Country EssayChild Memories EssayDiscrimination And Segregation EssaysSingle Mothers Struggle Survive EssayLiterature Review On EducationDerek Mahon Leaving Cert EssayEmbroidery EssaysSample Of Marketing Plan For Small BusinessAccess To Social Work Course

The phrase of what number represents the whole and is the unknown quantity.

We will let variable x represent this unknown quantity in our proportion.

PERCENT is the unknown quantity in our proportion, to be represented by n.

Substitute: becomes Solve: Cross multiply and we get: 56n = 14(100), or 56n = 1400 Divide both sides by 56 and we get: n = 25 Solution: 25% of 56 is 14 Problem 6: 18 is 75% of what number?

Substitute: Now we can substitute these values into our proportion.

becomes Solve: Cross multiply and we get: 40x = 18(100) or 40x = 1800 Divide both sides by 40 to solve for x and we get: x = 45 Solution: 18 is 40% of 45 Problem 3: What is 20% of 45?The phrase what percent tells us that percent is the unknown quantity.This unknown quantity will be represented by x in our proportion. Substitute: Now we can substitute these values into our proportion.Identify: 18 is the part and will replace IS in our proportion.75% means that 75 will replace PERCENT in our proportion.becomes Solve: Cross multiply and we get: 100x = 45(20) or 100x = 900 Divide both sides by 100 to solve for x and we get: x = 9 Solution: 9 is 20% of 45 In Problems 1, 2 and 3 we are given two numbers and asked to find the third by using a proportion.However, the unknown quantity was different for each problem. Red is used for the unknown quantity in each problem.But what would you do if you given this problem: 8 is what percent of 20?In this problem, the percent is the unknown quantity! Looking at this problem, it is clear that 8 is the part and 20 is the whole.In previous lessons, you were shown how to convert a decimal to a percent and a percent to a decimal.Thus, if you were asked to Find 15% of 120, you would multiply .15 by 120, to get an answer of 18.


Comments Solving Proportion Problems

The Latest from ©