Solution required for a Mathematical problem.?

Question

A bag contains 4 red and 5 black balls. Two balls are drawn at random. What is the probability that both of them are of the same color? If possible, a step-by-step please.

Answer 1

The probability that both are the same color is equal to the
sum of the probability that both are red, and the probability that
both are blue.
Since 4/9 of the balls are red, the probability the first ball is red is 4/9. If that happens then there are now 3 red balls and 5 black, so the probability that second is red is 3/8. Multiplying these you get 12/72=1/6.

Using a similar process for black you get (5/9)(4/8)=20/72=5/18.
1/6 + 5/18 = 8/18=4/9.

Answer 2

p(2 black or 2 red) = p (2 black)+p(2 red)
p(2 black)= 5/9 x 1/2 = 5/18
p(2 reds) = 4/9 x 3/8 = 12/72 = 1/6
Then p (2black or 2 red) = 5/18+1/6 = 4/9

Answer 3

Multiply the threat of a red ball on the first draw, it truly is 7/12 (there are 7 balls and 12 entire balls), via the threat of a red ball on the 2d draw, it truly is 7/12 or 6/11. it truly is the position some added techniques is needed. Is the red ball from the first draw replaced? no matter if it truly is, the threat remains a similar. If that's no longer replaced, there are literally 6 red balls and 11 entire balls. the answer is hence both 40 9/one hundred forty four without replace or 7/22 with.