Question

not able to understand the question at 1st place.. plz explain me this..

Answer 1

Answer:

Step-by-step explanation:

This answer is similar to your question put your case in this and solve for your answer.

Answer 2

Answer: 10 blue balls.

Step-by-step explanation:

Let number of blue balls be x.

Number of red balls= 5

So total number of balls in the bag will be (x+5).  

Probability (drawing a blue ball)= x / x+5

Probability (drawing a red ball)= 5 / x+5

Now, it is given that:

Probability (drawing a blue ball)= 2 [Probability (drawing a red ball)]

i.e., x/x+5= 2(5/x+5)

x/ x+5 = 10/ x+5

x= 10