Direct and Inverse Proportions Class 8 Case Study Questions Maths Chapter 11

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Last Updated on October 17, 2024 by XAM CONTENT

Hello students, we are providing case study questions for class 8 maths. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 8 maths. In this article, you will find case study questions for CBSE Class 8 Maths Chapter 11 Direct and Inverse Proportions. It is a part of Case Study Questions for CBSE Class 8 Maths Series.

ChapterDirect and Inverse Proportions
Type of QuestionsCase Study Questions
Nature of QuestionsCompetency Based Questions
BoardCBSE
Class8
SubjectMaths
Useful forClass 8 Studying Students
Answers providedYes
Difficulty levelMentioned
Important LinkClass 8 Maths Chapterwise Case Study

Case Study Questions on Direct and Inverse Proportions

Questions

Passage 1:

A hotel has 320 rooms and 32 cleaners to maintain them. With full capacity of staff, it took 2 hours to clean all the rooms.

Q. 1. On Monday 20% of the cleaners were not available. Will the cleaning of all rooms take more than 2 hours? How can you say so?

Difficulty Level: Easy

Sol. Yes.
As, Number of man required to complete work is inversely proportional to time taken by them.

Q. 2. Ishan says, “The number cleaners available in the hotel is directly proportional to the time taken by them to clean the rooms.”
Mira says, “The number of cleaners available in the hotel is inversely proportional to the time taken by them to clean the rooms.”
Who is correct? Give reason.

Difficulty Level: Medium

Sol. Mira is correct,
As Number of cleaners are inversely proportional to time taken

Q. 3. Equal number of rooms are allocated for each staff member for cleaning. How many rooms each cleaner had to maintain?

Difficulty Level: Easy

Sol. Number of rooms = 320
Number of cleaners = 32
Number of rooms cleaned by each cleaner = 320 / 32 = 10

Q. 4. The hotel administration hired 8 more cleaners. What is the change in number of rooms maintained by each cleaner?

Difficulty Level: Easy

Ans. Option (b) is correct.
Explanation: Number of cleaners = 40 (32 + 8)
Number of rooms cleaned by each cleaner = 320 / 40 = 8
So, Number of rooms decreased by (10 – 8) = 2

Q. 5. How many rooms has to be cleaned in an hour by each cleaner after the increase in the number of staff? (
(a) 1
(b) 4
(c) 8
(d) 10

Difficulty Level: Easy

Ans. Option (b) is correct.
Explanation: Number of rooms to be cleaned in 2 hours = 8
Number of rooms to be cleaned in 1 hour = 8/2 = 4

Also check

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Topics from which case study questions may be asked

  • Direct Proportions
  • Inverse Proportion

Whenever two quantities have a relation with each other such that if one changes, the other also changes then these quantities are said to be inter related with each other. This is called variation.

Example: (a) If number of something purchased increases then cost also increases.
(b) If speed of vehicle increases, time taken decreases.

Quantities increasing or decreasing together need not be in direct proportion or indirect proportion.

Case study questions from the above given topic may be asked.

Frequently Asked Questions (FAQs) on Direct and Inverse Proportions Case Study

Q1: What is direct proportion?

A1: Direct proportion refers to a relationship between two quantities where an increase in one quantity leads to a proportional increase in the other, and a decrease in one result in a proportional decrease in the other. Mathematically, two quantities x and y are in direct proportion if x/y=k, where k is a constant.

Q2: What is inverse proportion?

A2: Inverse proportion describes a relationship between two quantities where an increase in one quantity leads to a proportional decrease in the other and vice versa. In this case, the product of the two quantities remains constant. Mathematically, two quantities x and y are in inverse proportion if x × y = k, where k is a constant.

Q3: How can I identify if two quantities are in direct proportion?

A3: – To identify if two quantities are in direct proportion, check if their ratio remains constant when they change. If the ratio of the two quantities stays the same, they are in direct proportion. For example, if 4 pencils cost ₹20, and 8 pencils cost ₹40, the ratio of pencils to price remains constant, indicating direct proportion.

Q4: How can I identify if two quantities are in inverse proportion?

A4: To determine if two quantities are in inverse proportion, check if the product of the two quantities remains constant when they change. If multiplying the two quantities always gives the same result, they are in inverse proportion. For example, if 4 workers take 6 days to complete a task, and 8 workers take 3 days, the product of workers and days (4 × 6 = 24 and 8 × 3 = 24) remains constant, indicating inverse proportion.

Q5: Can you give a real-life example of direct proportion?

A5: A common real-life example of direct proportion is the relationship between distance and time when speed is constant. If a car travels at a constant speed, doubling the time will double the distance covered, maintaining a constant ratio between distance and time.

Q6: Can you provide an example of inverse proportion in daily life?

A6: A typical example of inverse proportion is the relationship between the number of workers and the time taken to complete a task. If more workers are assigned to a job, the time required to finish the work decreases proportionally, assuming the work is equally distributed among the workers.

Q7: Why is learning about direct and inverse proportions important?

A7: Understanding direct and inverse proportions is crucial as these concepts are frequently used in real-life situations, such as calculating speed, cost, work efficiency, and more. Mastery of these concepts helps students develop problem-solving skills and apply mathematical relationships to practical problems.

Q8: Are there any online resources or tools available for practicing Direct and Inverse Proportions case study questions?

A8: We provide case study questions for CBSE Class 8 Maths on our website. Students can visit the website and practice sufficient case study questions and prepare for their exams. If you need more case study questions, then you can visit Physics Gurukul website. they are having a large collection of case study questions for all classes.

Direct and Inverse Proportions Class 8 Case Study Questions Maths Chapter 11

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