A school has 500 students, and 60% of them are girls. How many girls are there in the school?

Correct Answer: B

Rationale: Correct! To find out how many girls are in the school, you need to calculate 60% of 500. 60% of 500 is 0.6 * 500 = 300. Therefore, there are 300 girls in the school. Choice A (250 girls) is incorrect because 60% of 500 is not 250. Choice C (200 girls) is incorrect as it is less than 300. Choice D (350 girls) is incorrect as it is more than 300.

Correct Answer: D

Rationale: To divide 4,7/8 by 1,1/6: Convert to improper fractions: 4,7/8 = 39/8 1,1/6 = 7/6 Divide by multiplying by the reciprocal: 39/8 6/7 = 234/56 Simplify: 234/56 = 117/28 or 4,5/28

Correct Answer: B

Rationale: To calculate the profit, first determine the total revenue: 7 stands * 11 paintings per stand * $5.50 per painting = $423.50. Then, subtract the total stand expenses ($35 per stand * 7 stands = $245) from the total revenue to get the profit: $423.50 - $245 = $178.50. Therefore, the correct answer is $178.50. Option A is incorrect because it does not account for the stand expenses. Option C is incorrect as it does not consider the total revenue. Option D is incorrect as it overestimates the profit by not deducting the stand expenses.

Correct Answer: D

Rationale: If Claire consumes 2,500 calories a day, Alice, consuming twice as many calories as Claire, would consume 2 * 2,500 = 5,000 calories per day. To find out how many calories Alice consumes per week, we multiply her daily consumption by 7 (days in a week): 5,000 * 7 = 35,000 calories. Therefore, Alice consumes 35,000 calories per week. Choices A, B, and C are incorrect because they do not account for Alice consuming twice as many calories as Claire.

Correct Answer: B

Rationale: The formula to calculate the perimeter of a square is P = 4s, where P is the perimeter and s is the length of a side. Given that the side length is 5 meters, the perimeter is 4 * 5 = 20 meters. Therefore, the correct answer is B. Choices A (15 meters), C (25 meters), and D (30 meters) are incorrect as they do not correctly apply the formula to calculate the perimeter of a square.

Correct Answer: A

Rationale: To add mixed numbers, first convert them to improper fractions. 6 3/4 = 27/4 and 8 1/6 = 49/6. Finding a common denominator, we get 27/4 + 49/6 = 81/12 + 98/12 = 179/12 = 14 & 11/12. Therefore, the correct answer is A. Choice B is incorrect as it does not simplify to the correct result. Choice C is in fraction form and not in mixed number form, making it incorrect. Choice D is not the correct sum of the given mixed numbers, so it is also incorrect.

Correct Answer: B

Rationale: The normal range for potassium levels is typically considered to be between 3.5 to 5.3 mmol/L. In this case, the potassium level of 4.5 mmol/L falls within this normal range. Therefore, the correct answer is that it is within the normal range (Choice B). Choice A is incorrect as 4.5 mmol/L is not too low. Choice C is also incorrect as 4.5 mmol/L is not too high. Choice D is incorrect as the given information is sufficient to determine that the potassium level is within the normal range.

Correct Answer: D

Rationale: The runner left at 7:45 and returned at 10:00, which means he ran for 2 hours and 15 minutes (10:00 - 7:45). At an average speed of 6 mph, in 2.25 hours, he would have covered 6 mph * 2.25 hours = 13.5 miles. Therefore, the correct answer is 13.5 miles. Choices A, B, and C are incorrect because they incorrectly calculate the distance based on the time and speed provided in the question.

Correct Answer: A

Rationale: To find the rate of calories burned per mile, you divide the total calories burned by the total miles run: 2274 calories / 21.6 miles = 105.28 calories per mile. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not match the calculated value. The rate of calories burned per mile is a precise calculation based on the given values, and only choice A aligns with the correct calculation.