RML MAINS 2025
Non Nursing Subjects
Hard
If 3 litres cost ₹145, find the cost of 4.5 litres.
Appeared in: RML MAINS 2025
Explanation
- The problem is solved using the unitary method, which involves finding the cost of a single unit (1 litre) first.
- Step 1: Calculate the cost of 1 litre by dividing the total cost by the number of litres: ₹145 / 3 litres = ₹48.33 per litre.
- Step 2: Multiply the cost per litre by the desired quantity to find the final answer: ₹48.33 × 4.5 litres = ₹217.5.
- Alternatively, using the ratio and proportion method: (3 litres / ₹145) = (4.5 litres / x). Solving for x gives 3x = 145 × 4.5, which results in x = ₹217.5.
Why Other Options Were Wrong
- Option A: This value is an underestimation. It would imply a cost per litre of approximately ₹44.44 (200 / 4.5), which is incorrect.
- Option B: This value is also an underestimation. It implies a cost per litre of about ₹46.67 (210 / 4.5), which is less than the actual rate of ₹48.33.
- Option D: This value is an overestimation. It would mean the cost per litre is ₹50 (225 / 4.5), which is higher than the rate calculated from the problem statement.
Related Visual
Clinical Relevance
- Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Solving a word problem using the unitary method or ratio and proportion as background academic context rather than a clinical decision trigger.
- Basic mathematical skills like ratio and proportion are fundamental for safe nursing practice, especially in medication administration.
- Nurses use these calculations daily to determine correct drug dosages, calculate IV drip rates, and reconstitute medications from powders, as highlighted in nursing fundamentals textbooks.
- Errors in calculation can lead to significant patient harm from underdosing or overdosing, making mathematical proficiency a critical nursing competency.
How to Approach the Question
- First, identify the known relationship provided in the question: 3 litres cost ₹145.
- Next, determine the goal: to find the cost of a different quantity, which is 4.5 litres.
- Recognize this as a proportion problem that can be solved efficiently using the unitary method.
- Step 1: Calculate the value of a single unit (the cost per litre) by dividing the total cost by the given quantity: ₹145 ÷ 3.
- Step 2: Multiply this single unit value by the new quantity for which you need to find the cost: (₹145 / 3) × 4.5.
- Perform the calculation carefully and match the result with the given options to find the correct answer.
Concept Tested & Keywords
- Concept Tested: Solving a word problem using the unitary method or ratio and proportion.
- Stem keywords: 3 litres, cost ₹145, 4.5 litres
- Lead-in keywords: find the cost
Question ID
QzkQMwQ0A8uYeU3e3UrjC0
Reference Book
E6 Nursing Fundamentals Potter Perry 12e Part 3 p. 141-143
Practise the full RML MAINS 2025
Attempt every question from this paper in a timed mock, then review the full solution for each one.
More Mathematics Questions
- 15 years hence a man will be just 4 times as old as he was 15 years ago. His present age is -?
- The ratio of number of girls to boys in a school of 2520 students is 27:29. How many more girls should be admitted to make the ratio 1:1?
- Three candidates contested an election and received 4500, 7500 and 8000 votes respectively. What percentage of votes did the winning candidates get?
- A man rows downstream at 15 km/hr and against the stream at 9 km/hr. His speed in still water is:
- Two bells ring at intervals of 59 seconds and 70 seconds. If they both ring at 10 O'clock in the morning together, after how many seconds will they r…
- The average of four numbers is 61. The largest number among them is 85 and the smallest number is 21. What will be the larger of the remaining two nu…
- In what ratio should water be mixed with milk so that on selling the mixture at cost price a profit of 20% is made?
- A quality control analyst rejects 0.08% of the fabric produced, finding it defective. How many meters of fabric must he examine to reject 4 meters?
- A man traveled from his village to the post office at a speed of 25km/hr and returned at a speed of 4km/hr. If the entire journey took 5 hours and 48…
- A train is running at 60 km/hr. How much time will it require to cross a 2 km bridge?
More RML MAINS 2025 Questions
- What is the minimum birth weight considered as low birth weight in Americans?
- Which one of the following statements is false about sterile gloves?
- Which one of the following measures are not recommended to prevent pressure ulcer?
- The client's postoperative orders state to advance the diet as tolerated. The client has been NPO; the nurse will advance the client's diet to clear…
- Which of the following statements indicates the nurse has the right understanding of the drug Digoxin while explaining its action to the patient?
- Which of the following drugs is commonly administered for a patient with supraventricular tachycardia which also has a short half-life?
- Complementary feeding for a 6-month-old baby includes:
- Causative agent of Chickenpox is:
- Why is an unconscious patient placed in the left lateral position?
- A nurse is preparing to collect a throat swab for culture from a child with suspected pharyngitis, from which site should the specimen be collected?