

Ex 13.4
Ex 13.4, 2
Ex 13.4, 3 Important
Ex 13.4, 4 (i)
Ex 13.4, 4 (ii)
Ex 13.4, 4 (iii) Important
Ex 13.4, 5 (i) Important
Ex 13.4, 5 (ii)
Ex 13.4, 6 Important
Ex 13.4, 7 Important
Ex 13.4, 8
Ex 13.4, 9
Ex 13.4, 10 Deleted for CBSE Board 2022 Exams
Ex 13.4, 11 Important Deleted for CBSE Board 2022 Exams
Ex 13.4, 12 Important Deleted for CBSE Board 2022 Exams
Ex 13.4, 13 Important Deleted for CBSE Board 2022 Exams
Ex 13.4, 14 Deleted for CBSE Board 2022 Exams
Ex 13.4, 15 Deleted for CBSE Board 2022 Exams
Ex 13.4, 16 (MCQ) Deleted for CBSE Board 2022 Exams You are here
Ex 13.4, 17 (MCQ) Important Deleted for CBSE Board 2022 Exams
Last updated at Aug. 11, 2021 by Teachoo
Ex 13.4, 16 The mean of the numbers obtained on throwing a die having written 1 on three faces, 2 on two faces and 5 on one face is (A) 1 (B) 2 (C) 5 (D) 83 Let, X be the number obtained on throwing the die Since on throwing a die, we can get 1, 2 or 5 Value of X can be 1, 2 or 5 So, The Probability are given by P(X = 1) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑓𝑎𝑐𝑒𝑠 1 𝑖𝑠 𝑤𝑟𝑖𝑡𝑡𝑒𝑛 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑐𝑒𝑠 = 36 = 12 P(X = 2) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑓𝑎𝑐𝑒𝑠 2 𝑖𝑠 𝑤𝑟𝑖𝑡𝑡𝑒𝑛 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑐𝑒𝑠 = 26 = 13 P(x = 5) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑓𝑎𝑐𝑒𝑠 5 𝑖𝑠 𝑤𝑟𝑖𝑡𝑡𝑒𝑛 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑐𝑒𝑠 = 16 Hence the Probability distribution : The Mean of the number is given by 𝝁=𝑬 𝑿= 𝑖 = 1𝑛𝑥𝑖𝑝𝑖 = 1 × 12+2 × 13+ 5 × 16 = 12+ 23+ 56 = 3 + 4 + 56 = 126 = 2 Hence option B is correct