Question

A bag contain 5 red balls and some blue balls. if the probability of drawing a blue ball is double that of red balls. find the number of blue in the bag

Answer 1

Hey fab ,

Let the number of blue balls be x .
Number of red balls = 5 .
Total balls = ( x + 5 ) .

Now ,
p ( red balls ) = 5 / x+5

And ,
p ( blue balls ) = x/x+5

Guve that , probability of drawing blue ball is double that of red balls .

So ,
2 * 5 / x + 5 = x / x+ 5
=> 10 / x+5 = x/x+5
=> 10 = x .

So , number of blue balls is = 10

Complicated Life :(