Class 8 Maths MCQs on Direct Proportion and Word Problems
Class 8 Maths MCQs on Direct Proportion and Word Problems
Class: 8
Subject: Mathematics
Chapter 7: Proportional Reasoning
Topic: Direct Proportion & Applications
Subject: Mathematics
Chapter 7: Proportional Reasoning
Topic: Direct Proportion & Applications
Strictly Based on CBSE Curriculum | As per NCERT Textbook | Ideal for CBSE Class 8 Examination Preparation
Q1. Two quantities are in direct proportion if:
Correct Answer: B) Their ratio is constant
Explanation: In direct proportion, y/x = constant.
Explanation: In direct proportion, y/x = constant.
Q2. If 5 pens cost ₹50, cost of 10 pens is:
Correct Answer: B) ₹100
Explanation: Cost doubles as quantity doubles.
Explanation: Cost doubles as quantity doubles.
Q3. If 3 notebooks cost ₹45, cost of 6 notebooks is:
Correct Answer: C) ₹90
Explanation: 45 × 2 = 90.
Explanation: 45 × 2 = 90.
Q4. If 8 workers complete work in 5 days, 16 workers will take:
Correct Answer: C) 2.5 days
Explanation: More workers, less time (inverse actually). But proportionally 8×5 = 16×x → x=2.5.
Explanation: More workers, less time (inverse actually). But proportionally 8×5 = 16×x → x=2.5.
Q5. If 4 meters cost ₹200, cost of 10 meters is:
Correct Answer: B) ₹500
Explanation: 200 ÷ 4 = 50 per meter; 10×50=500.
Explanation: 200 ÷ 4 = 50 per meter; 10×50=500.
Q6. If 2 kg apples cost ₹120, cost of 5 kg is:
Correct Answer: C) ₹300
Explanation: 120÷2=60 per kg; 5×60=300.
Explanation: 120÷2=60 per kg; 5×60=300.
Q7. If 12 books weigh 6 kg, 24 books weigh:
Correct Answer: B) 12 kg
Explanation: Weight doubles.
Explanation: Weight doubles.
Q8. If 3 litres petrol cost ₹300, cost of 7 litres is:
Correct Answer: C) ₹700
Explanation: 300÷3=100 per litre; 7×100=700.
Explanation: 300÷3=100 per litre; 7×100=700.
Q9. In direct proportion graph is:
Correct Answer: B) Straight line through origin
Explanation: y = kx.
Explanation: y = kx.
Q10. If 15 kg rice costs ₹750, cost per kg is:
Correct Answer: C) ₹50
Explanation: 750÷15=50.
Explanation: 750÷15=50.
Q11. If 9 chairs cost ₹1800, cost of 3 chairs is:
Correct Answer: A) ₹600
Explanation: 1800÷9=200; 3×200=600.
Explanation: 1800÷9=200; 3×200=600.
Q12. If 4 pencils cost ₹20, 12 pencils cost:
Correct Answer: C) ₹60
Explanation: 20÷4=5 per pencil; 12×5=60.
Explanation: 20÷4=5 per pencil; 12×5=60.
Q13. If 7 kg sugar costs ₹350, cost of 14 kg is:
Correct Answer: C) ₹700
Explanation: Doubles.
Explanation: Doubles.
Q14. If 6 hours earn ₹900, 1 hour earns:
Correct Answer: B) ₹150
Explanation: 900÷6=150.
Explanation: 900÷6=150.
Q15. If 5 identical machines produce 500 items, 10 machines produce:
Correct Answer: C) 1000
Explanation: Direct proportion.
Explanation: Direct proportion.
Q16. If 2 buses carry 80 passengers, 5 buses carry:
Correct Answer: C) 200
Explanation: 80÷2=40 per bus; 5×40=200.
Explanation: 80÷2=40 per bus; 5×40=200.
Q17. If 3 kg oranges cost ₹150, cost of 1 kg is:
Correct Answer: C) ₹50
Explanation: 150÷3=50.
Explanation: 150÷3=50.
Q18. If 4 identical taps fill tank in 6 hours, 8 taps fill in:
Correct Answer: A) 3 hours
Explanation: More taps, less time (inverse relation).
Explanation: More taps, less time (inverse relation).
Q19. If 10 m cloth costs ₹500, 25 m costs:
Correct Answer: D) ₹1250
Explanation: 500÷10=50; 25×50=1250.
Explanation: 500÷10=50; 25×50=1250.
Q20. In direct proportion, if one quantity increases, the other:
Correct Answer: C) Increases
Explanation: Both change in same ratio.
Explanation: Both change in same ratio.
