Question 16 - CBSE Class 10 Sample Paper for 2024 Boards - Maths Standard - Solutions of Sample Papers for Class 10 Boards
Last updated at July 21, 2023 by Teachoo
There is a square board of side '2a' units circumscribing a red circle. Jayadev asked to keep a dot on the above said board. The probability that he keeps the dot on the shaded region is.
(a) π/4 (b) (4-π)/4 (c) (π - 4)/4 (d) 4/π
Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class
Probability of placing a dot on shaded region
= (𝐴𝑟𝑒𝑎 𝑜𝑓 𝑠ℎ𝑎𝑑𝑒𝑑 𝑟𝑒𝑔𝑖𝑜𝑛 (𝑏𝑙𝑢𝑒))/(𝑇𝑜𝑡𝑎𝑙 𝑎𝑟𝑒𝑎)
= (𝑨𝒓𝒆𝒂 𝒐𝒇 𝒔𝒒𝒖𝒂𝒓𝒆 − 𝑨𝒓𝒆𝒂 𝒐𝒇 𝒄𝒊𝒓𝒄𝒍𝒆)/(𝑨𝒓𝒆𝒂 𝒐𝒇 𝒄𝒊𝒓𝒄𝒍𝒆)
Area of square
Side = 2a
Area = 〖(2𝑎)〗^2 =〖 𝟒𝒂〗^𝟐 units
Area of circle
Radius of circle = 2𝑎/2 = a
Area of circle = π𝑎^2
Now,
Probability of placing a dot on shaded region
= (𝑨𝒓𝒆𝒂 𝒐𝒇 𝒔𝒒𝒖𝒂𝒓𝒆 − 𝑨𝒓𝒆𝒂 𝒐𝒇 𝒄𝒊𝒓𝒄𝒍𝒆)/(𝑨𝒓𝒆𝒂 𝒐𝒇 𝒄𝒊𝒓𝒄𝒍𝒆)
= (4𝑎^2−𝜋𝑎^2)/(4𝑎^2 )
= ((4 − 𝜋 ) 𝑎^2)/〖 4𝑎〗^2
= (4 − 𝜋)/4So, the correct answer is (b)
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.
Hi, it looks like you're using AdBlock :(
Displaying ads are our only source of revenue. To help Teachoo create more content, and view the ad-free version of Teachooo... please purchase Teachoo Black subscription.
Please login to view more pages. It's free :)
Teachoo gives you a better experience when you're logged in. Please login :)
Solve all your doubts with Teachoo Black!
Teachoo answers all your questions if you are a Black user!