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Converting Among Percents, Decimals, Fractions, and Percent Word Problems Practice Questions

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Updated on Oct 3, 2011

To review these concepts, go to Converting Among Percents, Decimals, Fractions, and Percent Word Problems Study Guide.

Converting Among Percents, Decimals, Fractions, and Percent Word Problems Practice Questions

Practice 1

Problems

Match the decimal or fraction from column 1 with the correct percent in column 2.

Solutions

Practice 2

Problems

  1. 40 out of 50 is what percent?
  2. 140% of 20 is what number?
  3. 10.5 is 2% of what number?
  4. What number is 45% of 80?

Solutions

  1. Read and understand the question. This question is asking for the percent one number is of another number.
  2. Make a plan. Use the proportion This question is looking for the percent, so place x over 100. The number after the word of is 50, so 50 is the whole. The number 40 is the part.

    Carry out the plan. Set up the proportion: Cross multiply to get 50x = 4,000. Divide each side of the equation by 50.

      x = 80%

    40 out of 50 is equal to 80%.

    Check your answer. Substitute the solution into the proportion to check this answer. The proportion is The cross products are each 4,000, so this answer is checking.

  3. Read and understand the question. This question is looking for the percent of a number.
  4. Make a plan. Use the proportion . This question gives the value 140%, so place 140 over 100. The number after the word of is 20, so 20 is the whole. The phrase what number appears after the word is, so x is the part.

    Carry out the plan. Set up the proportion. . Cross multiply to get 100x = 2,800. Divide each side of the equation by 100.

      x = 28

    28 is 140% of 20.

    Check your answer. Substitute the solution into the proportion to check this answer. The proportion is . The cross products are each 2,800, so this answer is checking.

  5. Read and understand the question. This question is asking for a number when the part of the number is given.
  6. Make a plan. Use the proportion . This question is looking for the whole (the number after the word of ) so place x in the denominator of the first fraction. The number before the word is is 10.5, so 10.5 is the part, or the numerator of the first fraction. The percent given in the question is 2%, so place 2 over 100 in the proportion.

    Carry out the plan. Set up the proportion. . Cross multiply to get 2x = 1,050. Divide each side of the equation by 2.

      x = 525

    10.5 is 2% of 525.

    Check your answer. Check this solution by finding 2% of 525. This is equal to 0.02 × 525 = 10.5, so this problem is checking.

  7. Read and understand the question. This question is looking for the percent of a number.
  8. Make a plan. Use the proportion . This question gives the value 45%, so place 45 over 100. The number after the word of is 80, so 80 is the whole. The phrase what number appears before the word is, so x is the part.

    Carry out the plan. Set up the proportion: . Cross multiply to get 100x = 3,600. Divide each side of the equation by 100.

      x = 36

    36 is 45% of 80.

    Check your answer. Substitute the solution into the proportion to check this answer. The proportion is . The cross products are each 3,600, so this answer is checking.

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