A vertical stick 20m long casts a shadow 10m long on the ground. At the same time a tower casts a shadow 50m long. What is the height of the tower?

(a) 30m   (b) 50m   (c) 80m   (d) 100m

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  1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards

Transcript

Question 39 A vertical stick 20m long casts a shadow 10m long on the ground. At the same time a tower casts a shadow 50m long. What is the height of the tower? (a) 30m (b) 50m (c) 80m (d) 100m Since the triangles are similar Their sides are proportional (๐‘ฏ๐’†๐’Š๐’ˆ๐’‰๐’• ๐’๐’‡ ๐’”๐’•๐’Š๐’„๐’Œ)/(๐‘ณ๐’†๐’๐’ˆ๐’•๐’‰ ๐’๐’‡ ๐’”๐’‰๐’‚๐’…๐’๐’˜ ๐’๐’‡ ๐’”๐’•๐’Š๐’„๐’Œ)=(๐‘ฏ๐’†๐’Š๐’ˆ๐’‰๐’• ๐’๐’‡ ๐‘ป๐’๐’˜๐’†๐’“)/(๐‘ณ๐’†๐’๐’ˆ๐’•๐’‰ ๐’๐’‡ ๐’”๐’‰๐’‚๐’…๐’๐’˜ ๐’๐’‡ ๐‘ป๐’๐’˜๐’†๐’“) 20/10=(๐‘ฏ๐’†๐’Š๐’ˆ๐’‰๐’• ๐’๐’‡ ๐‘ป๐’๐’˜๐’†๐’“)/50 2 =(๐ป๐‘’๐‘–๐‘”โ„Ž๐‘ก ๐‘œ๐‘“ ๐‘‡๐‘œ๐‘ค๐‘’๐‘Ÿ)/50 2 ร— 50 = Height of tower Height of tower = 100 m So, the correct answer is (d)

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.