Fresh grapes contain 80% water by weight, whereas dried grapes contain 15% water by weight. How many kilograms of dried grapes can be obtained from 13.6 kg of fresh grapes?

1. A

   2.95

2. B

   3.6

3. C

   3.2

4. D

   2.72

Appeared in: PGIMER Chandigarh NO - 2015

Explanation

• The core concept is that the non-water component (pulp) remains constant in weight during the drying process.
• First, calculate the weight of the pulp in the fresh grapes: 13.6 kg of fresh grapes with 80% water means 20% is pulp. So, pulp weight = 13.6 kg * 0.20 = 2.72 kg.
• This constant pulp weight of 2.72 kg makes up 85% of the dried grapes' total weight (since dried grapes are 15% water).
• To find the total weight of the dried grapes (W), set up the equation: 0.85 * W = 2.72 kg.
• Solving for W gives: W = 2.72 / 0.85 = 3.2 kg.

Why Other Options Were Wrong

• Option A: This value is the result of an incorrect calculation and does not follow the logic of constant pulp mass.
• Option B: This value is the result of an incorrect calculation. If the final weight were 3.6 kg, the pulp percentage would be (2.72 / 3.6) * 100 = 75.6%, not the required 85%.
• Option D: This is a common distractor. 2.72 kg is the weight of the solid pulp only, not the total weight of the dried grapes. The question asks for the total weight, which includes the pulp plus the remaining 15% water.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Quantitative Aptitude - Percentages and Mixtures as background academic context rather than a clinical decision trigger.
• This question tests quantitative aptitude and logical reasoning, which are essential skills for nurses.
• Nurses frequently perform calculations for medication dosages, IV drip rates, and fluid balance monitoring, all of which require strong mathematical proficiency.
• What if the dried grapes contained 25% water? The pulp would be 75% of the total weight. The new total weight would be 2.72 kg / 0.75 = 3.63 kg.

How to Approach the Question

• First, read the question carefully to understand the initial and final states (fresh vs. dried grapes) and their compositions.
• Identify the component that remains constant throughout the process. In this case, it's the solid pulp; only the water evaporates.
• Calculate the absolute weight of this constant component using the initial total weight and percentage. (Pulp weight = 13.6 kg * 20%).
• Use this absolute weight to determine the total weight of the final mixture. The pulp's weight (2.72 kg) is 85% of the final mixture's weight.
• Set up an equation (0.85 * Total Weight = 2.72) and solve for the total weight.
• Double-check your answer and be wary of distractors, such as the weight of the pulp alone (2.72 kg).

Concept Tested & Keywords

• Concept Tested: Quantitative Aptitude - Percentages and Mixtures
• Stem keywords: fresh grapes, dried grapes, water, weight, kilograms, percentage
• Lead-in keywords: How many

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