Ex 13.2, 13 - Chapter 13 Class 12 Probability (Term 2)
Last updated at Dec. 8, 2020 by Teachoo
Independent events
Ex 13.2, 6
Ex 13.2, 10 Important
Ex 13.2, 5
Example 10
Example 11 Important
Example 12 Important
Ex 13.2, 15 (i)
Ex 13.2, 8
Ex 13.2, 7 Important
Ex 13.2, 11 (i)
Ex 13.2, 4
Ex 13.2, 13 Important You are here
Ex 13.2, 14 Important
Ex 13.2, 18 (MCQ) Important
Example 13 Important
Example 14 Important
Independent events
Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (i) both balls are red.Two balls are drawn with replacement from a box Given Number of black balls in box = 10 Number of red balls in box = 8 Total number of balls in box = 10 + 8 = 18 P(both balls are red) = P(first ball is red) × P(second ball is red given first is red) = 8/18 × 8/18 = 4/9 × 4/9 = 𝟏𝟔/𝟖𝟏 Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (ii) first ball is black and second is red.P (first ball is black & second is red) = P(first ball is black) × P(second ball is red given first is black) = 10/18 × 8/18 = 5/9 × 4/9 = 𝟐𝟎/𝟖𝟏 Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (iii) one of them is black and other is red.P(one ball is black & other is red) = P(first ball is black & second is red) + P(first ball is red & second is black) = (10/18×8/18)+(8/18×10/18) = 2 × (10/18×8/18) = 𝟒𝟎/𝟖𝟏