A bag contains 4 red and 7 blue balls. What is the probability of drawing a blue ball if the first ball drawn is red? The balls drawn are not replaced in the bag.

Category: QuestionsA bag contains 4 red and 7 blue balls. What is the probability of drawing a blue ball if the first ball drawn is red? The balls drawn are not replaced in the bag.
Editor">Editor Staff asked 11 months ago

A bag contains 4 red and 7 blue balls. What is the probability of drawing a blue ball if the first ball drawn is red? The balls drawn are not replaced in the bag.
 
(a) \frac {7}{10}
 
 
(b) \frac {8}{10}
 
 
(c) \frac {7}{1}
 
 
(d) \frac {4}{11}
 
 
I have been asked this question during an online exam.
 
This interesting question is from Multiplication Theorem on Probability topic in division Probability of Mathematics – Class 12
NCERT Solutions for Subject Clas 12 Math Select the correct answer from above options 
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1 Answers
Editor">Editor Staff answered 11 months ago

The correct option is (a)
7
10
 
 
To explain I would say: Total number of balls = 4 + 7 = 11
 
The probability of the first ball to be red =
4
11
 
 
The probability of drawing blue ball as the second ball out without replacement =
7
10