The average temperature for Sunday, Monday, Tuesday and Wednesday is 60 degree, and the average for Monday, Tuesday, Wednesday and Thursday is 63 degree. If the ratio of temperatures for Sunday and Thursday be 21:25, find the temperature on Thursday:

1. A

   75 degree

2. B

   75 degree

3. C

   65 degree

4. D

   63 degree

Appeared in: ESIC Nursing Officer 2016 (shift-1)

Explanation

• The sum of temperatures for Sunday, Monday, Tuesday, and Wednesday is 60 × 4 = 240 degrees.
• The sum of temperatures for Monday, Tuesday, Wednesday, and Thursday is 63 × 4 = 252 degrees.
• Subtracting the first sum from the second gives the difference between Thursday's and Sunday's temperature: Thursday - Sunday = 252 - 240 = 12 degrees.
• The ratio of temperatures for Sunday and Thursday is 21:25. Let the temperatures be 21x and 25x, respectively.
• The difference is 25x - 21x = 4x, which equals 12 degrees. Therefore, x = 12 / 4 = 3.
• The temperature on Thursday is 25x = 25 × 3 = 75 degrees.

Why Other Options Were Wrong

• Option B: This is a duplicate of the correct answer. While the value is correct, it's listed as the second option, and typically only the first correct instance is chosen.
• Option C: 65 degrees is an incorrect calculation. If Thursday's temperature were 65, Sunday's would have to be 53 (65-12), which does not match the 21:25 ratio.
• Option D: 63 degrees is the average temperature for the second set of days (Monday-Thursday), not the specific temperature for Thursday. This is a common error of misinterpreting the question's request.

Related Visual

• Visual 1: No visual is required for this type of mathematical problem.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Problem-solving using Averages and Ratios as background academic context rather than a clinical decision trigger.
• This question tests basic arithmetic and problem-solving skills, which are fundamental for nurses.
• Nurses frequently use calculations for medication dosages, IV drip rates, and interpreting patient data, making numeracy a critical competency.
• What if the ratio was 4:5 and the difference was 12? Then 5x - 4x = 12, so x=12. Thursday's temperature would be 5x = 5 * 12 = 60 degrees. This shows how changing the ratio alters the final answer.

How to Approach the Question

• First, identify the information given in the problem: two average temperatures for two overlapping sets of days, and a ratio between the temperatures of two specific days.
• Translate the word problem into mathematical equations. Use the formula for average: Sum of values / Number of values.
• Calculate the sum of temperatures for each four-day period by multiplying the average by the number of days (4).
• Subtract the two sums to eliminate the common days (Monday, Tuesday, Wednesday) and isolate the difference between the unique days (Sunday and Thursday).
• Use the given ratio to express the temperature of one day in terms of the other using a variable (e.g., 21x and 25x).
• Substitute this expression into the difference equation and solve for the variable 'x'.

Concept Tested & Keywords

• Concept Tested: Problem-solving using Averages and Ratios
• Stem keywords: average temperature, Sunday, Monday, Tuesday, Wednesday, Thursday, ratio
• Lead-in keywords: find the temperature

Question ID

QPnDZ_0S_WA6tlS3zjbCNB

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