In a local baseball team, 4 players, which represent 5% of the team, have long hair, and the rest have short hair. How many short-haired players are there on the team?

Correct Answer: C

Rationale: Given that 4 players represent 5% of the team, let's denote the total number of players as x. The equation to represent this situation is 0.05x = 4. Solving for x, we get x = 80, which is the total number of players on the team. Since 4 players have long hair, the remaining players have short hair, which is 80 - 4 = 76. Therefore, there are 76 short-haired players on the team. Choices A, B, and D are incorrect as they do not consider the total number of players correctly, leading to inaccurate calculations.

Correct Answer: A

Rationale: When 45% of the babies were girls, it means the remaining 55% were boys. To determine the number of boys, calculate 55% of 76, which equals approximately 41.8, rounding up to 42. Therefore, 42 boys were born last night at the hospital. Choice B, C, and D are incorrect as they do not reflect the accurate calculation of the number of boys born.

Correct Answer: C

Rationale: Calculate the increase in dosage: 100mg * 20% = 100mg * 0.20 = 20mg. Add the increase to the original dosage to find the new dosage: 100mg + 20mg = 120mg. Therefore, the new dosage is 120mg after a 20% increase from the original 100mg dosage. Choice A (80mg) is incorrect because it represents a decrease rather than an increase. Choice B (100mg) is the original dosage and does not account for the 20% increase. Choice D (140mg) is incorrect as it is the original dosage plus 40%, not the 20% increase specified.

Correct Answer: C

Rationale: To add mixed numbers, convert them to improper fractions. 7 2/3 = 23/3 and 5 5/12 = 65/12. Adding them results in 233/12. Converting this improper fraction back to a mixed number gives 19 5/12, which simplifies to 13 1/12. Therefore, the correct answer is 13 1/12.\nChoice A (11 1/12) is incorrect as it does not represent the correct sum of the given mixed numbers. Choice B (12 1/4) is incorrect as it is not the result of adding 7 2/3 and 5 5/12. Choice D (14 1/6) is incorrect as it is not the correct sum of the provided mixed numbers.

Correct Answer: D

Rationale: To find the amount of medication delivered in one hour, we first calculate the amount delivered in one minute by multiplying the number of drops per minute (40) by the volume of each drop (0.05 milliliters). This gives us 2 milliliters per minute. Then, to find the total amount delivered in one hour, we multiply 2 milliliters per minute by the number of minutes in an hour (60), resulting in 120 milliliters. Therefore, the correct answer is 120 milliliters. Choices A, B, and C are incorrect as they do not correctly calculate the total volume of medication delivered in one hour.

Correct Answer: B

Rationale: To determine the percentage of income remaining after spending 15%, subtract the percentage spent from 100% (100% - 15% = 85%). Therefore, Mary has 85% of her income left, which aligns with answer choice B. Choice A (12%) is incorrect because it represents the remaining amount after spending 88% of her income. Choice C (75%) is incorrect as it does not account for the 15% already spent. Choice D (95%) is incorrect as it does not consider the amount spent by Mary.

Correct Answer: A

Rationale: To convert milliliters to liters, you divide by 1000 since 1000 milliliters make up 1 liter. In this case, 5000 milliliters divided by 1000 milliliters per liter equals 5 liters (5000 mL · 1000 mL/L = 5 L). Therefore, the correct answer is A: 5 liters. Choice B, 4 liters, is incorrect because 5000 milliliters is equivalent to 5 liters, not 4. Choice C, 6 liters, is incorrect as it is not the accurate conversion from milliliters to liters in this case. Choice D, 5.5 liters, is incorrect as it does not reflect the correct conversion of 5000 milliliters to liters, which is 5 liters.

Correct Answer: C

Rationale: In Roman numerals, XL represents 40, and IV represents 4. When XL (40) is combined with IV (4), it forms XLIV, which corresponds to the number 44. Therefore, the correct answer is 44. Choice A (34) is incorrect as it does not consider the value of XL and IV. Choice B (54) is incorrect as it miscalculates the value of XL. Choice D (24) is incorrect as it does not account for the value of XL.

Correct Answer: D

Rationale: To find the total surface area, we need to calculate the surface area of the cylindrical body and both hemispherical ends separately. The surface area of the cylinder is the sum of the lateral surface area (2πrh) and the area of the two circular bases (2πr^2). For the hemispheres, the surface area of one hemisphere is (2πr^2), so for two hemispheres, it would be (4πr^2). Given that the diameter of the cylinder and hemispherical ends is 10cm, the radius (r) is 5cm. Calculating the individual surface areas: Cylinder = 2π(5)(20) + 2π(5)^2 = 200π + 50π = 250π. Hemispheres = 4π(5)^2 = 100π. Adding these together gives a total surface area of 250π + 100π = 350π cm^2, which is approximately equal to 2055 sq cm. Therefore, the correct answer is D. Choice A (785 sq cm) is incorrect as it is significantly lower than the correct calculation. Choices B (1130 sq cm) and C (1570 sq cm) are also incorrect as they do not reflect the accurate surface area calculation for the given dimensions.