Nokea
Jessica buys 10 cans of paint. Red paint costs $1 per can, and blue paint costs $2 per can. In total, she spends $16. How many red cans did she buy?
- A. 2
- B. 3
- C. 4
- D. 5
Correct Answer: C
Rationale: Let r be the number of red cans and b be the number of blue cans. The total cans equation is r + b = 10. The total cost equation is r + 2b = 16. By solving these equations simultaneously, we find r = 4. Therefore, Jessica bought 4 red cans. Choice A, 2 red cans, is incorrect because it does not satisfy the total cans or total cost condition. Choices B and D are also incorrect as they do not fulfill both conditions simultaneously.
You may also like to solve these questions
If ð‘› = 8, then n is between which of the following ranges?
- A. 5 and 7
- B. 7 and 9
- C. 9 and 11
- D. 3 and 5
Correct Answer: B
Rationale: To find the range where n lies when n = 8, we consider numbers greater and lesser than 8. The range would be between 7 and 9, not 9 and 11 as stated in the original rationale. Option A (5 and 7) and Option D (3 and 5) are lower ranges, while Option C (9 and 11) exceeds the upper limit.
Your measurement of the width of a door is 36 inches. The actual width of the door is 35.75 inches. What is the relative error in your measurement?
- A. 0.70%
- B. 0.01%
- C. 0.99%
- D. 0.10%
Correct Answer: A
Rationale: To calculate relative error, you use the formula: (|measured value - actual value| / actual value) * 100%. Substituting the values, we get (|36 - 35.75| / 35.75) * 100% = (0.25 / 35.75) * 100% = 0.7%. This means your measurement is off by 0.7% from the actual width of the door. Choice B, 0.01%, is too small as it doesn't reflect the actual difference. Choices C and D are significantly different from the calculated answer and do not represent the accurate relative error in the measurement.
Which operation should be completed first in the expression 8 + 5 * 3?
- A. Multiplication
- B. Addition
- C. Division
- D. Subtraction
Correct Answer: A
Rationale: The correct answer is 'Multiplication.' In the expression 8 + 5 * 3, according to the order of operations (PEMDAS), multiplication should be done before addition. PEMDAS stands for Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right). Therefore, the multiplication operation should be completed first, making 5 * 3 equal to 15, and then the addition operation should be conducted to get the final result of 8 + 15, which equals 23. Choices B, C, and D are incorrect because in this expression, multiplication takes precedence over addition, division, and subtraction according to the order of operations.
Four people split a bill. The first person pays for 1/3, the second person pays for 1/4, and the third person pays for 1/6. What fraction of the bill does the fourth person pay?
- A. 1/4
- B. 1/6
- C. 1/3
- D. 1/12
Correct Answer: D
Rationale: To find out what fraction of the bill the fourth person pays, you first calculate the total fraction paid by the first three people: 1/3 + 1/4 + 1/6 = 4/12 + 3/12 + 2/12 = 9/12 = 3/4. This means that the first three people paid 3/4 of the bill. Therefore, the fourth person pays the remaining fraction: 1 - 3/4 = 1/4. So, the fourth person pays 1/4 of the bill. Choice A, 1/4, is incorrect because this is the total fraction paid by the first person. Choice B, 1/6, is incorrect as this is the fraction paid by the second person. Choice C, 1/3, is incorrect as this is the fraction paid by the third person.
How will 0.80 be written as a percent?
- A. 40%
- B. 125%
- C. 90%
- D. 80%
Correct Answer: D
Rationale: To convert a decimal to a percent, you multiply by 100. Therefore, 0.80 * 100 = 80%. The correct answer is D. Choice A (40%) is incorrect as 0.80 is not equivalent to 40%. Choice B (125%) is incorrect as it is greater than 100%. Choice C (90%) is incorrect as it does not reflect the correct conversion of 0.80 to a percent.