Questions pratiques sur les pourcentages et les ratios PARCC
1. Rick renovated his home. He made his bedroom 40% larger (length and width) than its original size. If the original dimensions were 144 inches by 168 inches, how big is his room now if measured in feet?
1. B. 144 X 0.40 = 57.6 + 144 = 201.6 and 168 X 0.40 = 67.2 + 168 = 235.2; then convert to feet 201.6/12 = 16.8 ft and 235.2/12 = 19.6 ft.
2. Maria paid $28.00 for a jacket that was discounted by 30%. What was the original price of the jacket?
2. C. If X represents the original price of the jacket and Y represents the discounted amount, then 0.30X = Y and X - Y = 28; X - 0.30X = 28; 0.70X = 28; X = = 40.
3. Derek received 6 job offers from the 15 interviews he did last month. Which ratio best describes the relationship between the number of jobs he was not offered and the number of jobs for which he interviewed?
3. C. The number of jobs he did not get is 15 - 6 = 9. The ratio is 9:15 or 3:5.
4. Gordon purchased a television when his local electronics store had a sale. The television was offered at 30% off its original price of $472. What was the sale price that Gordon paid?
4. D: The television is 30% off its original price of $472. 30% of 472 is 141.60, and 141.60 subtracted from 472 is 330.40. Thus, Gordon pays $330.40 for the television.
5. Within a certain nursing program, 25% of the class wanted to work with infants, 60% of the class wanted to work with the elderly, 10% of the class wanted to assist general practitioners in private practices, and the rest were undecided. What fraction of the class wanted to work with the elderly?
5. C: According to the problem statement, 60% of the class wanted to work with the elderly. Therefore, convert 60% to a fraction by using the following steps: 60% = 60/100 Now simplify the above fraction using a greatest common factor of 20. 60/100 = 3/5
6. Veronica has to create the holiday schedule for the neonatal unit at her hospital. She knows that 35% of the staff members will not be available because they are taking vacation days during the holiday. Of the remaining staff members who will be available, only 20% are certified to work in the neonatal unit. What percentage of the TOTAL staff is certified and available to work in the neonatal unit during the holiday?
6. B: Since 35% of the staff will take vacation days, only 100% - 35% = 65% of the staff is available to work. Of the remaining 65%, only 20% are certified to work in the neonatal unit. Therefore multiply 65% by 20% using these steps: Convert 65% and 20% into decimals by dividing both numbers by 100. 65/100 = 0.65 and 20/100 = 0.20 Now multiply 0.65 by 0.20 to get (0.65)(0.20) = 0.13 Now convert 0.13 to a percentage by multiplying by 100. 0.13)(100) = 13%
7. A patient requires a 30% decrease in the dosage of his medication. His current dosage is 340 mg. What will his dosage be after the decrease?
7. B: The patient's dosage must decrease by 30%. So calculate 30% of 340: (0.30)(340 mg) = 102 mg Now subtract the 30% decrease from the original dosage. 340 mg - 102 mg = 238 mg
8. A study about anorexia was conducted on 100 patients. Within that patient population 70% were women, and 10% of the men were overweight as children. How many male patients in the study were NOT overweight as children?
8. C: Since 70% of the patients in the study were women, 30% of the patients were men. Calculate the number of male patients by multiplying 100 by 0.30. (100)(0.30) = 30 Of the 30 male patients in the study, 10% were overweight as children. So 90% were not overweight. Multiply 30 by 0.90 to get the final answer. (30)(0.90) = 27
9. Susan is extremely excited about starting her first job as a nurse. Her gross annual salary is $40,000. Susan contributes 10% of her salary before taxes to a retirement account. Then she pays 25% of her remaining salary in state and federal taxes. Finally, she pays $30 per month for health insurance. What is Susan's annual take-home pay?
9. C: Susan receives $40,000. First she contributes 10% of her salary to a retirement account. ($40,000)(0.10) = $4000 $40,000 - $4000 = $36,000 After contributing to her retirement account, Susan has $36,000 left. Then she pays 25% in taxes. ($36,000)(0.25) = 9,000 $36,000 - $9,000 = $27,000 After paying taxes, Susan has $27,000 left. Finally, she pays $30 each month for health insurance. Calculate the annual amount Susan pays for health insurance, and subtract this amount from her remaining salary. ($30)(12) = $360 $27,000 - $360 = $26,640
10. In order for a school to allow a vending machine to be placed next to the cafeteria, 65% of the school's population must ask for it. If 340 of the school's 650 students have requested the vending machines, how many more are needed to get the vending machines?
10. B: (650 students x .65 = 422.5) 422.5 - 340 = 82.5 ≈ 83 more students