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Example 4 - A train is moving at a uniform speed of 75 km/hour

Example 4 - Chapter 13 Class 8 Direct and Inverse Proportions - Part 2
Example 4 - Chapter 13 Class 8 Direct and Inverse Proportions - Part 3 Example 4 - Chapter 13 Class 8 Direct and Inverse Proportions - Part 4

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Example 4 A train is moving at a uniform speed of 75 km/hour. (i) How far will it travel in 20 minutes? Given, Train is moving at a uniform speed of 75 km/hour ∴ Distance travelled by train in 1 hour = 75 km i.e. Distance travelled by train in 60 minutes = 75 km We need to find how far will the train travel in 60 minutes Let train travel x km Thus, our table looks like Now, as distance increases time taken to travel also increases ∴ They are in direct proportion. 75/60 = 𝑥/20 75/60 × 20= 𝑥 75/3 = 𝑥 25 = 𝑥 𝑥 = 25 km ∴ Train will travel 25 km Example 4 A train is moving at a uniform speed of 75 km/hour. (ii) Find the time required to cover a distance of 250 km. We need to find time required to cover a distance of 250 km Let time required be y minutes Thus, our table looks like Since distance and time are in direct proportion 75/60 = 250/𝑦 75 × y = 60 × 250 𝑦 = (60 × 250)/75 𝑦 = (4 × 250)/5 𝑦 = (4 × 50)/1 𝑦 = 200 minutes Converting to hours 𝑦 = 200/60 hours 𝑦 = 3 hours 20 min ∴ Train will require 3 hours 20 minutes

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.