Nokea
A scientific illustrator uses a scale of 3:1 for drawings of insects. If the length of a cicada in the drawing is 6 centimeters, how long is the actual cicada in real life?
- A. 18 centimeters
- B. 6.3 centimeters
- C. 4.6 centimeters
- D. 4.2 centimeters
Correct Answer: A
Rationale: The scale of 3:1 means that for every 3 centimeters in the drawing, it represents 1 centimeter in real life. If the length of the cicada in the drawing is 6 centimeters, in real life, it would be 6 x 3 = 18 centimeters long. Therefore, the actual length of the cicada in real life is 18 centimeters. Choice B, 6.3 centimeters, is incorrect because it does not account for the scale factor. Choices C and D, 4.6 centimeters and 4.2 centimeters respectively, are also incorrect as they do not consider the 3:1 scale used in the drawing.
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What is the result of dividing 3 by 4?
- A. 5.75
- B. 5.875
- C. 6.25
- D. 0.75
Correct Answer: D
Rationale: To divide 3 by 4, we perform the division operation: 3 · 4 = 0.75. The correct answer is 0.75 (D). Choices A, B, and C are incorrect because they do not result from dividing 3 by 4. Choice A (5.75) is the result of dividing 23 by 4, choice B (5.875) is the result of dividing 7 by 1.2, and choice C (6.25) is the result of multiplying 5 by 1.25.
Olivia currently earns $51,200 in her job. If her salary increases by 4% this year, what will her new salary be?
- A. $52,348
- B. $52,736
- C. $53,040
- D. $53,248
Correct Answer: D
Rationale: To find Olivia's new salary after a 4% increase, we calculate 4% of $51,200, which is 0.04 x $51,200 = $2,048. Adding this increase to Olivia's current salary gives us the new salary: $51,200 + $2,048 = $53,248. Therefore, Olivia's salary after the 4% increase will be $53,248. Choices A, B, and C are incorrect as they do not reflect the correct calculation for the new salary after a 4% increase.
A plan for a barn is drawn on a 1:30 scale. If the width of a barn door on the plan measures 3 inches, what is the actual width of the finished door?
- A. 90 inches
- B. 10 feet
- C. 9 feet
- D. 7.5 feet
Correct Answer: B
Rationale: The scale of 1:30 means that 1 inch on the plan represents 30 inches in actual size. If the width of the barn door on the plan is 3 inches, the actual width is calculated by multiplying 3 inches by the scale factor (30), giving 90 inches. To convert inches to feet, divide by 12 (since 12 inches = 1 foot), resulting in 90 inches · 12 = 7.5 feet. Therefore, the correct answer is 10 feet (option B), not 7.5 feet. Option A (90 inches) is the result before converting to feet, option C (9 feet) is the incorrect conversion if the initial calculation was done correctly, and option D (7.5 feet) is the incorrect conversion of the initial calculation.
A bottle of hand sanitizer contains 70% alcohol. If 5ml of sanitizer are used, how much pure alcohol is present?
- A. 1.4ml
- B. 2.1ml
- C. 2.8ml
- D. 3.5ml
Correct Answer: B
Rationale: Rationale:
- If the hand sanitizer contains 70% alcohol, it means that 70% of the 5ml used is pure alcohol.
- To find the amount of pure alcohol present, we calculate 70% of 5ml: 0.7 * 5ml = 3.5ml.
- Therefore, when 5ml of sanitizer are used, there are 3.5ml of pure alcohol present.
If the total cost of his purchase was $9.38 and he gave the cashier $20, how much change did he receive?
- A. $0.62
- B. $5.02
- C. $9.38
- D. $10.62
Correct Answer: D
Rationale: To determine the amount of change received, you need to subtract the total cost from the amount given. $20 - $9.38 = $10.62. Therefore, he received $10.62 in change. Option A ($0.62) is incorrect as it is the difference in cents, not dollars. Option B ($5.02) is incorrect as it does not reflect the correct subtraction. Option C ($9.38) is incorrect as it represents the total cost of the purchase, not the change received.