Question

20. A box contains 12 balls out of which x are black,

(i) If one ball is drawn at random from the box , what is the probability that it will be a black

ball?

(ii) If 6 more black balls are added in the bag ,probability of drawing a black ball will be

double than in (i). Find x



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Answer 1

Answer:

hope it may help you...........

Answer 2

Answer:

x=3

Step-by-step explanation:

Total number of balls=12

Let the number of black balls be x

P(drawing a black balls)=x/12

It is given than 6 more black balls are put in the box

Now,we have:

Total number of balls=18

Number of black balls=x+16

P(drawing a black ball)=x+6/18

Therefore,we have:

x+6/18=2×x/12

x+6/18=x/6

x+6=3x

x-3x=6

2x=6

x=6/2

x=3

And last wherever l have given the slash it means for eg:x+6upon 18

Please see that while writing wherever the slash is there it means upon