Question

a bay contain 4 white balls and some red balls.if the probability of drawing a white ball from the bag is 2/5,find the number of ball in the bag​

Answer 1

Answer:

Total number of balls were 10.......4 white and 6 red.... therefore the probability of drawing becomes 4/10 which is 2/5 .

Answer 2

Answer:

Solution :

A bag contains 4 white balls and some red balls .

Let us assume that the number of red balls present in the bag is x.

The total number of balls present in the bag becomes ( x + 6) . This is the sample space .

Now, the probability of drawing a white ball :

> [ Number of favorable events ]/[ Total number of events ]

> [ 4 ]/[ x + 6]

But, the probability of drawing a white ball is 2/5 .

So,

4/(x+6) = 2/5

> 2(x+5) = 20

> 2x + 10 = 20

> 2x = 10

> x = 5.

Thus, there are 5 red balls in the bag,

This is the required answer.

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