There are 6,657 marbles in a jar. Approximately 34% are white, and the rest are black. How many black marbles are there?
- A. 4,394
- B. 4,000
- C. 3,000
- D. 5,000
Correct Answer: A
Rationale: To find the number of black marbles, we need to calculate the percentage that represents the black marbles, which is 100% - 34% = 66%. Then, we find 66% of 6,657 to determine the number of black marbles. 66% of 6,657 is approximately 4,394, so there are 4,394 black marbles in the jar. Choice A is correct. Choices B, C, and D are incorrect as they do not reflect the correct calculation for the number of black marbles in the jar.
You may also like to solve these questions
Convert 5 3/4 to a decimal. Round to the nearest tenth.
- A. 5.6
- B. 5.7
- C. 5.8
- D. 6
Correct Answer: C
Rationale: To convert 5 3/4 to a decimal, we add the whole number part to the fractional part: 5 + 3/4 = 5.75. Rounding 5.75 to the nearest tenth gives us 5.8. Therefore, the correct answer is C. Choice A (5.6) is incorrect because it does not accurately represent 5 3/4. Choice B (5.7) is incorrect as well because it does not reflect the correct conversion. Choice D (6) is incorrect as it does not account for the fractional part of 5 3/4.
If 9 out of 75 band members missed practice, what percentage of band members missed practice?
- A. 10%
- B. 12%
- C. 15%
- D. 18%
Correct Answer: B
Rationale: To calculate the percentage of band members who missed practice, divide the number of members who missed practice (9) by the total number of band members (75) and multiply by 100. (9/75) * 100 = 12%. Therefore, 12% of the band members missed practice. Choice A (10%) is incorrect because it is not the correct calculation result. Choices C (15%) and D (18%) are also incorrect as they do not reflect the accurate percentage of band members who missed practice.
How much paint do you need to paint the interior walls and floor of a rectangular swimming pool with dimensions 8m by 5m and a depth of 2m? (Assume one can of paint covers 10 sq m)
- A. 56 sq m
- B. 72 sq m
- C. 88 sq m
- D. 104 sq m
Correct Answer: C
Rationale: To calculate the total area to be painted, find the area of each wall and the floor, sum them up, and subtract the area of the top surface of the pool. The area to be painted is (2*8 + 2*5 + 8*5) = 16 + 10 + 40 = 66 sq m. Since one can of paint covers 10 sq m, divide the total area (66 sq m) by the coverage area per can to determine the number of cans needed. Therefore, you need 88 sq m of paint, which is equivalent to 9 cans of paint. Choice A, B, and D are incorrect as they do not represent the correct calculation of the total area to be painted.
Jeff needed a 6 ft. rope. He found 2 pieces of rope and thought maybe he could tie them together. One rope was 40 inches and the other was 36 inches. How long would the rope be, and would he have enough rope if he ties them together?
- A. No, the rope would be 76 inches.
- B. Yes, the rope would be 76 inches.
- C. Yes, the rope would be 6 feet.
- D. No, the rope would be 6 feet.
Correct Answer: B
Rationale: To convert 6 feet to inches, we multiply 6 by 12 (1 foot = 12 inches), giving us 72 inches needed. By adding the lengths of the two ropes (40 inches + 36 inches), Jeff would have a total of 76 inches, which is more than the 72 inches required. Therefore, he would have enough rope if he ties them together. Choice A and D are incorrect because they misinterpret the conversion from feet to inches. Choice C is incorrect as it does not consider the actual combined length of the two ropes.
The physician ordered 16 mg of Ibuprofen per kg of body weight; on hand are 80 mg tablets. The child weighs 15 kg. How many tablets will you give?
- A. 3 tablets
- B. 2 tablets
- C. 1 tablet
- D. 2.5 tablets
Correct Answer: B
Rationale: To calculate the total dose required for the child, multiply the child's weight (15 kg) by the prescribed dose per kg (16 mg/kg): 15 kg * 16 mg/kg = 240 mg. Next, determine how many tablets are needed to reach this total dose: 240 mg / 80 mg per tablet = 3 tablets. However, since you cannot give a fraction of a tablet, the correct answer is 2 tablets. Choice A is incorrect because it miscalculates the number of tablets needed. Choice C is incorrect because only 1 tablet is not sufficient to reach the required dose. Choice D is incorrect because you cannot give a partial tablet, so it has to be rounded down to the nearest whole tablet.