A cell has a diameter of 0.1 meter, and another cell has a diameter of 0.05 meters. How many times larger is the first cell compared to the second cell?

Correct Answer: A

Rationale: To determine how many times larger the first cell is compared to the second cell, divide the diameter of the first cell by the diameter of the second cell: 0.1 / 0.05 = 2. Therefore, the first cell is 2 times larger than the second cell. Choice B, C, and D are incorrect because they do not provide the accurate calculation for the size difference between the two cells.

Correct Answer: D

Rationale: To find the fourth vertex of a parallelogram, we can use the properties of a parallelogram. Opposite sides of a parallelogram are parallel and equal in length. Therefore, we can determine the fourth vertex by extending the line formed by the first two points. If we extend the line from (1, 2) to (3, 4), we find that it has a slope of 1. This means that extending the line from (3, 4) by the same slope will give us the fourth vertex. By adding 2 units to both x and y coordinates of (5, 6), we get (7, 8) as the coordinates of the fourth vertex. Therefore, the correct answer is (7, 8). Choices A, B, and C are incorrect as they do not satisfy the properties of a parallelogram and the given coordinate points.

Correct Answer: A

Rationale: To convert liters to kiloliters, divide by 1000 since there are 1000 liters in a kiloliter. Therefore, 147 liters = 0.147 kiloliters. Choice B is incorrect as it incorrectly moves the decimal point. Choices C and D are significantly larger than the correct answer, indicating an incorrect conversion factor used.

Correct Answer: A

Rationale: To multiply fractions, multiply the numerators together and the denominators together. Multiplying 3/5 by 5/7 gives (3*5)/(5*7) = 15/35. This fraction simplifies to 3/7 by dividing the numerator and denominator by their greatest common factor, which is 5. Therefore, the correct answer is 3/7. Choices B, C, and D are incorrect as they do not result from multiplying 3/5 by 5/7.

Correct Answer: A

Rationale: To multiply fractions, multiply the numerators together and the denominators together. For (3/5) * (5/8), you get (3*5) / (5*8) = 15 / 40, which simplifies to 3/8. Therefore, the correct answer is A. Choice B (3/5) is incorrect as it is one of the original fractions being multiplied. Choice C (15/40) is the result of the multiplication but not simplified to its lowest terms. Choice D (3/30) is incorrect as the numerator is not the result of multiplying 3 and 5 together.

Correct Answer: D

Rationale: When simplifying the expression 3x - 5x + 2, start by combining like terms. -5x is subtracted from 3x to give -2x. Adding 2 at the end gives the simplified expression -2x. Therefore, the correct answer is -2x. Choice A, -2x + 2, incorrectly adds 2 at the end. Choice B, -8x, incorrectly combines the coefficients of x without considering the constant term. Choice C, 2x + 2, incorrectly adds the coefficients of x without simplifying.

Correct Answer: A

Rationale: To convert fluid ounces to gallons, you need to divide the number of fluid ounces by the number of fluid ounces in a gallon. Since there are 128 fluid ounces in a gallon, to find out how many gallons are in 1,000 fluid ounces, you divide 1,000 by 128. The correct calculation is 1,000 / 128 = 7.8125 gallons. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not accurately represent the conversion from fluid ounces to gallons.

Correct Answer: A

Rationale: The correct answer is A, which is -15. When you multiply -3 by 5, you get -15. The negative sign in front of the 3 indicates a negative value, and when multiplied by a positive number like 5, the result remains negative. Choices B, C, and D are incorrect because they do not reflect the correct multiplication of -3 and 5.

Correct Answer: B

Rationale: To find the median of a set of numbers, you arrange them in ascending order and then find the middle value. Given the data set 3, 5, 7, 9, 11, when arranged in ascending order, becomes 3, 5, 7, 9, 11. The middle value in this set is 7, making it the median. Choice A (3) is the smallest value, not the middle value. Choice C (9) and Choice D (5) are not the middle values of the set either. Therefore, the correct answer is B (7).