Question

21) a bag contains 5 red and 4 black balls.four balls are drawn at random.in how many ways can we draw so that there are exactly 2 red balls? ​

Answer 1

Answer:

Step-by-step explanation:

If I pick the red ball first and the black one next we have a probability of  59×12=518  ( 12  because after I draw the red ball there are exactly  4  red and  4  black balls in the box, so the chance to draw a black one is  48  or  12  simplefied).

If I pick the black ball first the probability is  49×58=518 .

Combining these two probabilities we get  518+518=59

And other way to see it is this: the chance to pick two red ones is  518  (see the calculation above) the chance of picking two black ones is  49×38=16

And  1−(518+16)=59

Answer 2

Answer:

8/9 IS THE PROBABILITY!!!

Step-by-step explanation:

NUMBER OF RED BALLS = 5

NUMBER OF BLACK BALLS = 4

TOTAL NUMBER OF BALLS = 4+5

                                               = 9

SO,

A.T.Q.,

8/9 IS THE PROBABILITY

I HOPE YOU UNDERSTOOD THE QUESTION!!!