Lesson Percentage Word Problems (discount)

This Lesson (Percentage Word Problems (discount)) was created by by mathick(4)

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A typical word problem involving percentages might look something like this:

Ned got a 12% discount when he bought his new jacket. If the original price, before the discount, was $50, how much was the discount?

Word problems tend to be even wordier than this one. The solution process involves making the problem simpler and simpler, until it's a math problem with no words.

Step 1. Identify what they're asking for, and call it x.

x = amount of the discount.

Step 2. Use the information given to write an equation that relates the quantities involved.

12% of 50 dollars = the amount of the discount (x).

Step 3. Translate into Math:

(12/100) * 50 = x.

Step 4. Solve for x:

6 = x.

This means that Ned's 12% off amounted to a $6 discount.

A few examples of some word problems using this method are in the table below. You can try a sample problem if you'd like to practice and see if you're doing it correctly.

Problems: A. The original price was $160, and Ned got a 20% discount? How much was the discount? B. The original price was $90, and Ned got a $36 discount. How many percent off was the discount? C. Ned's discount was 20% off the original price, which meant a $40 discount. What was the original price?

Write an equation: A. What is 20% of 160? B. 36 is what percent of 90? C. 40 is 20% of what number?

Translate into math:
is = “=”
of = “*”
What = “x”
5% = “5/100”, etc.

A. What is 20% of 160? x = (20/100) * 160. B. 36 is what % of 90? 36 = (x/100) * 90. C. 40 is 20% of what number? 40 = (20/100) * x.

Simplify & solve for x:
(This may involve solving a linear equation -
click here to practice.) A. x = (.2)*160, so x = 32 B. 36 = (.9)x, so x = 40 C. 40 = (.2)x, so x = 200

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