Nokea
What is the perimeter of a rectangle with a length of 12 cm and a width of 5 cm?
- A. 17 cm
- B. 24 cm
- C. 34 cm
- D. 40 cm
Correct Answer: C
Rationale: The correct formula for the perimeter of a rectangle is P = 2(l + w), where l represents the length and w represents the width. Substituting the given values into the formula: P = 2(12 cm + 5 cm) = 2(17 cm) = 34 cm. Therefore, the perimeter of the rectangle is 34 cm. Choice A (17 cm) is incorrect as it seems to have added only the length and width without multiplying by 2. Choice B (24 cm) is incorrect as it does not consider the multiplication by 2. Choice D (40 cm) is incorrect as it seems to have added the length and width without multiplying by 2.
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What is the area of a triangle with a base of 10 cm and a height of 7 cm?
- A. 70 cm²
- B. 35 cm²
- C. 140 cm²
- D. 100 cm²
Correct Answer: B
Rationale: To find the area of a triangle, you use the formula A = 1/2 base height. Substituting the given values: A = 1/2 10 cm 7 cm = 35 cm². Therefore, the correct answer is B. Choice A (70 cm²) is incorrect as it seems to be the product of the base and height rather than the area formula. Choice C (140 cm²) is incorrect as it appears to be twice the correct answer, possibly a result of a miscalculation. Choice D (100 cm²) is incorrect as it does not reflect the correct calculation based on the given base and height values.
Solve the equation 8x − 6 = 3x + 24. Which of the following is the correct solution?
- A. x = 2.5
- B. x = 3.6
- C. x = 5
- D. x = 6
Correct Answer: D
Rationale: To solve the equation 8x − 6 = 3x + 24, start by adding 6 to both sides: 8x − 6 + 6 = 3x + 24 + 6, which simplifies to 8x = 3x + 30. Next, subtract 3x from both sides to get 5x = 30. Finally, divide both sides by 5 to solve for x: x = 6. Therefore, the correct solution is x = 6. Choices A, B, and C are incorrect because they do not result from the correct algebraic manipulation of the equation.
Simplify the expression. What is the value of x? (5/4)x = 20
- A. 8
- B. 16
- C. 24
- D. 32
Correct Answer: D
Rationale: To solve for x, multiply both sides by the reciprocal of 5/4 to isolate x. (4/5)(5/4)x = (4/5)20; x = 16. Therefore, the correct answer is 32. Choice A (8), Choice B (16), and Choice C (24) are incorrect as they do not represent the correct value of x obtained after correctly simplifying the expression.
Which of the following is the correct solution to the equation 3x + 4 = 19?
- A. x = 3
- B. x = 4
- C. x = 5
- D. x = 6
Correct Answer: C
Rationale: To solve the equation 3x + 4 = 19, first, subtract 4 from both sides to isolate the term with x, which gives 3x = 15. Then, divide both sides by 3 to solve for x, resulting in x = 5. Therefore, the correct answer is x = 5. Choice A, x = 3, is incorrect as it does not satisfy the equation. Choice B, x = 4, is also incorrect as it does not make the equation true. Choice D, x = 6, is incorrect as it does not align with the correct solution obtained through the proper algebraic steps.
Melissa is ordering fencing to enclose a square area of 5625 square feet. How many feet of fencing does she need?
- A. 75 feet
- B. 150 feet
- C. 300 feet
- D. 5,625 feet
Correct Answer: C
Rationale: To find the side length of the square, we take the square root of the area: √5625 ft² = 75 ft. The perimeter of a square is 4 times its side length, so the fencing needed is 4 75 ft = 300 ft. Therefore, Melissa needs 300 feet of fencing to enclose the square area of 5625 square feet. Option A (75 feet) is the side length of the square, not the fencing needed. Option B (150 feet) is half of the correct answer and does not account for all sides of the square. Option D (5,625 feet) is the total area, not the length of fencing required.