Question 18 - NCERT Exemplar - MCQ - Chapter 14 Class 10 Probability

Last updated at April 16, 2024 by

A school has five houses A, B, C, D and E. A class has 23 students, 4 from house A, 8 from house B, 5 from house C, 2 from house D and rest from house E. A single student is selected at random to be the class monitor. The probability that the selected student is not from A, B and C is

(A) 4/23 

(B) 6/23      

(C) 8/23  

(D) 17/23  

 

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Transcript

Question 18 A school has five houses A, B, C, D and E. A class has 23 students, 4 from house A, 8 from house B, 5 from house C, 2 from house D and rest from house E. A single student is selected at random to be the class monitor. The probability that the selected student is not from A, B and C is (A) 4/23 (B) 6/23 (C) 8/23 (D) 17/23 Now, Number of students in A = 4 Number of students in B = 8 Number of students in C = 5 Number of students in D = 2 Number of students in E = 23 − (4 + 8 + 5 + 2) = 4 Now, Probability that the selected student is not from A, B and C = P(student is from D and E) = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑡𝑢𝑑𝑒𝑛𝑡𝑠 𝑖𝑛 𝐷 𝑎𝑛𝑑 𝐸)/(𝑇𝑜𝑡𝑎𝑙 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑡𝑢𝑑𝑒𝑛𝑡𝑠) = (2 + 4)/23 = 𝟔/𝟐𝟑 So, the correct answer is (B)

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.