Question

There are 6 black balls and some blue balls in a box. Without looking into the box, the probability of getting a black ball is 3/5. Find the number of blue balls in the box ​

Answer 1

Step-by-step explanation:

For 2 black , 1 white and 1 blue.

No. of ways are (4c2)*(5c1)*(6c1) = 180

For 1 black , 2 white and 1 blue.

No. of ways are (4c1)*(5c2)*(6c1) = 240

For 1 black , 1 white and 2 blue.

No. of ways are (4c1)*(5c1)*(6c2) = 300

Adding them gives us 720

Now Total no. of order (in which balls to be picked) are 12 (4!/2!)

So

final answer is 720 * 12 =

8640

Answer 2

Answer:

10

Step-by-step explanation:

10 will be the answer. The number of blue balls in the box is 10.