Correct Answer: A

Rationale: When rounding to the nearest hundredth, we look at the digit in the thousandth place, which is 8. Since the next digit, in the ten-thousandth place, is 9 (greater than or equal to 5), we round up the hundredth place digit. Therefore, 847.89632 rounded to the nearest hundredth is 847.90. Choice B (900) is incorrect as it does not round the number to the nearest hundredth. Choice C (847.89) is also incorrect as it drops the digit 6 in the ten-thousandth place. Choice D (847.896) does not round the number to the nearest hundredth as it retains the thousandth place digit 3.

Correct Answer: B

Rationale: To convert a decimal to a fraction, we note that 1.25 can be expressed as 1 + 0.25. Since 0.25 is equivalent to 25/100 or 1/4, we add 1 whole to 1/4 to get 1 1/4, which simplifies to 5/4. Therefore, 1.25 as a fraction is 5/4. Choice A (1 1/4) is the mixed number form of 5/4. Choice C (4/5) and Choice D (25/20) are incorrect fractions that do not represent 1.25.

Correct Answer: D

Rationale: To find the perimeter of a rectangle, you add the lengths of all its sides. In this case, the formula for the perimeter of a rectangle is 2*(length + width). Substituting the given values, we get: 2*(7 cm + 3 cm) = 2*(10 cm) = 20 cm. Therefore, the correct answer is 20 cm. Choice A (21 cm) is incorrect because it is the sum of the individual sides rather than the perimeter. Choice B (10 cm) is incorrect because it only represents one side of the rectangle. Choice C (14 cm) is incorrect as it is not the total perimeter of the rectangle.

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.

Correct Answer: A

Rationale: The slope of the equation C = 50 + 75D is 75. This means that for each additional gigabyte used (represented by D), the cost (represented by C) increases by 75 dollars. Therefore, the correct interpretation of the slope is that it is 75 dollars per gigabyte. Choice B, 75 gigabytes per day, is incorrect as the slope does not represent the rate of data usage per day. Choice C, 50 dollars per day, is incorrect as it does not reflect the relationship between gigabytes used and the cost. Choice D, 50 dollars per gigabyte, is incorrect as it does not match the slope value of 75 in the equation.