1. Chapter 13 Class 8 Direct and Inverse Proportions
  2. Serial order wise


Example 9 If 15 workers can build a wall in 48 hours, how many workers will be required to do the same work in 30 hours? Given, 15 workers can build a wall in 48 hours We need to find how many workers will do the same work in 30 hours Let the number of workers be x Thus, our table looks like As we increase the number of workers, time taken to build the wall decreases ∴ They are in inverse proportion 15 × 48 = 𝑥 × 30 (15 × 48)/30 = 𝑥 (1 × 48)/2 = 𝑥 24 = 𝑥 𝑥 = 24 ∴ 24 workers are required to build the wall (𝑥1𝑦1=𝑥2𝑦2)

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.