Percent: Word Problems 02:52 minutes

Video Transcript

Transcript Percent: Word Problems

Shannon is searching the Internet for some crime statistics for an article she's writing for her school newspaper. The statistics she found are a lot like word problems with percentages. Let's see what Shannon found out.

Percent Word Problems Example 1

What in the world...? Shannon finds out that five percent of all burglars take a selfie at the place where they commit the crime. Then, they post the picture on social media and are identified. So, If there are 40 burglars, how many of them took a selfie according to the statistics?

In this case, you need to calculate a percentage of the total number of burglars to find out how many of them took selfies.

If you have to find a certain percent of a number, you have to use multiplication. So we know we have to calculate 5% of 40, but first we must transform the percentage into a decimal first.

  • This is easy to do: you can write 5% as 5 over 100.
  • That is the same as 5 divided by 100, so just move the decimal point two places to the left and you get 0.05.
  • Now we multiply 0.05 by 40, giving us 2.

This means: if there are 40 burglars, 2 of them took a selfie.

Percent Word Problems Example 2

Shannon looks at another example. How silly is that?! 6 out of 20 burglars try to break in through the doggy door and have to be freed by firefighters. Let's see what percentage of burglars get caught in doggy doors.

  • We can write this as 6 over 20, or 6 divided by 20.
  • If we solve this by setting up an equation and using cross multiplication to solve for x. We can write: "6 over 20 is equal to what (x) percent?".
  • X % we can write as x over 100. So we get the equation 6 over 20 = x over 100.
  • Using cross multiplication, we get 6 · 100 = 20 · x.
  • After simplifying that and dividing both sides by 20, we get x = 30.

So this means 30 out of 100 or 30 percent of all burglars try to break in through the doggy door.

Percent Word Problems Example 3

Shannon looks at one last statistic. One out of every hundred thieves tries to blow up a safe to get to the money or jewelry inside. How do we express this as a percentage?

  • Out out of every hundred is the same as 1 out of 100, or 1 over 100.
  • To transfer this into a percent, you first divide 1 by 100, which is 0.01.
  • Now you move the decimal point two places to the right and put a percent sign after it.

So, 1 percent of all thieves try to blow up a safe. But most thieves are not successful.

1 comment
  1. Default

    Thank you for making this lesson so easy to understand! The video played without skipping and I could stay engaged the entire time.

    Posted by Usertest User1, over 2 years ago