Chapter 10: Proportional Reasoning-2 — Online MCQ Test

MATHS (KANITHA PRAKASH) · CLASS 8th · Karnataka State Board
Practice Chapter 10: Proportional Reasoning-2 with a free chapter-wise online MCQ test. This chapter covers: Direct Proportion Inverse Proportion Constant of Proportionality Ratio Proportion Pie Chart Circle Graph Data Representation Percentage Distribution Scale Factor Unitary Method Com.... AI-generated questions from basic to board-exam level, with instant results and explanations.

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Chapter 10: Proportional Reasoning-2 — Important Questions & Answers

If 5 notebooks cost ₹50, what is the cost of 1 notebook at the same rate?

A. ₹5
B. ₹10
C. ₹15
D. ₹25

Answer: B. ₹10
Using unitary method, cost of 1 notebook = 50 ÷ 5 = ₹10.

Which of the following is an example of direct proportion?

A. Number of workers and time taken to finish a fixed job
B. Distance travelled and time at constant speed
C. Speed and time for a fixed distance
D. Number of taps and time to fill a tank

Answer: B. Distance travelled and time at constant speed
At constant speed, distance increases as time increases, so the two quantities are in direct proportion.

If 8 kg of rice costs ₹360, what is the cost of 5 kg of the same rice?

A. ₹180
B. ₹200
C. ₹225
D. ₹240

Answer: C. ₹225
Cost per kg = 360 ÷ 8 = ₹45. Therefore, 5 kg costs 5 × 45 = ₹225.

A map uses a scale of 1 cm : 5 km. If two towns are 7.2 cm apart on the map, what is the actual distance?

A. 32 km
B. 36 km
C. 40 km
D. 45 km

Answer: B. 36 km
Actual distance = 7.2 × 5 = 36 km.

If 6 machines can complete a job in 14 days, how many machines are needed to complete the same job in 7 days?

A. 10
B. 12
C. 14
D. 16

Answer: B. 12
Machines and days are in inverse proportion. Total work = 6 × 14 = 84 machine-days, so 84 ÷ 7 = 12 machines.