Before solving a percent problem, you must first identify which numbers represent the PART and which numbers represent the WHOLE. What is 45% of 40? In this problem, 45% is the part and 40 is the whole. 100% (even though you don't actually see the number 100 anywhere) is also the whole. So, we are looking for the part that 45% is equal to. A proportion would look like this... $\frac{45}{100}=\frac{m}{40}$ Now you can solve the problem using any method you choose. 
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Remember: Percent means "per hundred", so in every percentage problem you solve, something will always be compared to 100. Often times when solving a percentage problem, you will need to identify two equivalent ratios, one of which will be a ratio involving "100". Directions:
Try using this applet to solve these questions...

Try these practice problems. Click the [show anwer] to check your work.
EXAMPLE 1 In a parking lot with 250 parking spaces, 40% of them are vacant. How many spaces are occupied? 
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EXAMPLE 2 A computer normally costs $600, but it is on sale for 35% OFF.

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EXAMPLE 3 On a test you got a 34/40. What percent of the problems did you answer correctly? 
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EXAMPLE 4 Jon has 12 stamps with boats on them. This is 40% of his collection. How many stamps are in his entire collection? 
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Question 1 Each year Charlotte donates 5% of her income to charity. If she donated $3000 last year, what was her total income? 
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Question 2 Tracy's soccer team scored 80 goals this year. Tracy scored 30% of those goals. How many goals did Tracy score? 
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Question 3 In a survey, 18 out of 24 people preferred Joe's Burgers over Patty's House of Burgers. What percent is this? 
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