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### Course: Class 7 (Old)>Unit 7

Lesson 2: Meaning of percentage

# Percent word problem: 78 is 15% of what number?

In this example, you working with us to find the number that is expressed as a given percentage. We'll create a simple algebraic equation to solve! Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• What is markup?
• why does the video have nothing to do with the questionsevertime
• What about problems that show everything but the %? What about a question that asks to find percentage?

For example: an Item is \$6.95 before tax, and after Tax it is \$7.61. How can I find the tax which is a percent?
• Try subtracting \$6.95 from \$7.61. If it dose not work, tell me please.
• 78 is 15% of what number?

Literally divide 78 by 0.15 and it gives you the answer.
The way shown in the video was pretty long.
• so in another way can we write another equation like this for this?^^
78/n = 15/100 ?
• Yes she is doing .15x=78 in a inequality form.
Hope this helps!
• there is two of the same videos
• `can we do it this way?78/n = 15/100 ?`
• Yes, that is a proportion though, here she is using a inequality. They both do the same thing in different ways.
Hope this helps!
• I don't understand 78 is 15% of what number, what do they mean by that??
• It means that the X is an unknown number and they want you to find that unknown number I think
• Why not just cross multiply