Q. 124.9( 11 Votes )

A box contains 12

Answer :

Given: total balls in the box = 12

Let number of red balls = x


Then probability of drawing a red ball = =


When 6 more red balls are put in the box,


Total balls in the box = 12 + 6 = 18


Red balls in the box = x + 6


Probability of drawing a red ball = =


According to the question, the probability of drawing a red ball when 6 red balls are added = 2(the probability of red ball drawn earlier)




x + 6 = 3x


3x – x = 6


2x = 6


x = 3


Thus, there are 3 red balls in the box.


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