Exercise 3.5: Cross-Multiplication and Word Problems
A mix of cross-multiplication technique and word problems involving ages, speeds, fractions, and money. This exercise tests whether you can set up equations from real situations.
Extra Practice Questions
These questions cover the same concepts as Exercise 3.5. Try solving them to build confidence before or after the textbook exercise.
For what value of 'k' will the following pair of linear equations have no solution? 3x + y = 1 (2k - 1)x + (k - 1)y = 2k + 1
The cost of 5 pens and 7 notebooks is ₹255, while the cost of 7 pens and 5 notebooks is ₹249. What is the cost of one pen and one notebook, respectively?
For the pair of linear equations: ax + by + c = 0 dx + ey + f = 0 Which of the following statements correctly represents the setup for finding 'x' using the cross-multiplication method?
For which value of 'k' will the pair of linear equations 3x + y = 1 and (2k - 1)x + (k - 1)y = 2k + 1 have no solution?
For a pair of linear equations in two variables, (x, y) = (p, q) is a solution if:
A point (a, b) is considered a solution to a pair of linear equations if:
For which value of 'p' will the following pair of linear equations have infinitely many solutions? px + 3y - (p - 3) = 0 12x + py - p = 0
Consider the system of linear equations a1x + b1y + c1 = 0 and a2x + b2y + c2 = 0. Which of the following statements must be true if a1b2 - a2b1 = 0 and b1c2 - b2c1 = 0?
Find the value of 'm' for which the pair of linear equations mx + y = 1 and (m² + 1)x + (m - 1)y = m has no solution.
Consider the pair of equations: Equation (1): x - 2y = 4 Equation (2): 3x + y = 5 Which method would be the most efficient to solve this particular system of equations and why?
Stuck on a question?
Paste any question from Exercise 3.5 into our AI Maths Solver and get a step-by-step solution instantly. It works for all NCERT questions.
Try AI Solver — FreeCommon Mistakes to Avoid
- ✗Setting up equations incorrectly from word problems
- ✗Forgetting units in the final answer
- ✗Not checking the solution makes sense in the real-world context
Other Exercises in Chapter 3
Frequently Asked Questions
How many questions are in Exercise 3.5?
Exercise 3.5 has 4 questions combining cross-multiplication with real-world word problems.
Is Exercise 3.5 important for boards?
Yes — word problems from this exercise are regularly asked for 3-4 marks in CBSE board papers.
Want to practise on paper? Download a free worksheet for this topic.
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