In the previous section, you solved word problems to determine which operations should be used. Once you successfully identified the operations, you saw how grouping symbols could be used to write expressions in order to solve the problem.

Not every problem comes with an expression that is ready to be solved. Usually, you will have to write that expression yourself. Using a problem-solving plan, like the example below, will help you to create that expression.

Practice

Use what you have seen in this resource to answer the following questions. Remember, you may need to convert rational numbers to an equivalent form or use a problem-solving plan.

1. Norma bought a television at a 25% discount. The original price of the television was $875. Norma also paid 7.5% sales tax. What is the final amount that Norma paid for the television?

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   Need a Hint?

   Convert each percent to a decimal. What operation do the clue words in the problem suggest you may need to perform?
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   Check Your Answer

   Amount of discount: 0.25 × $875 = $218.75
   Price of television: $875 – $218.75 = $656.25
   Amount of sales tax: $656.25 × 0.075 ≈ $49.22
   Final cost: $656.25 + $49.22 = $705.47
2. A plumber charges a service fee of $65 to come to a home and a labor charge of $75 per hour. If she works for 23 over 4 3 4 hours, what is the total amount of the bill? Use the grid below to record your answer. Type your answer in the boxes in front of and behind the decimal. Click inside each box to enter the numeral that belongs in the box, and then click the bubble beneath the numeral to shade the bubble that matches the numeral.



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Need a Hint?

Convert the number of hours to a decimal. Which number, $65 or $75, represents the hourly rate?
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Check Your Answer

Amount of bill = $65 + $75 × 2 3 over 4 3 4 = $65 + $75 × 2.75 = $65 + $206.25 = $271.25
3. Cristobal’s class took a survey of 25 students’ favorite foods. Ten of the 25 students chose hot dogs, 36% chose hamburgers, and the rest chose pizza. What percent of the students chose pizza?

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   Need a Hint?

   What percent does 10 out of 25 students represent?
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   Check Your Answer

   10 over 25 10 25 = 40 over 199 40 100 = 40%
   100% – (40% + 36%) = 24% chose pizza