Question fron Binomial Probability chapter: (1 Viewer)

[kooltrainer]

A) if 6 dices are rolled 100 times, how many times would u expect the number of even numbers showing to exceed the number of odd numbers showing?

B) tennis player finds that on average he gets his serve in 8 of every10 attempts and serves an ace in 1 of 15 serves . He serves 4 times. Find probability that he hits exactly 3 aces and the other serve lands in

ANSWER TO (A) = 34
ANSWER TO (B) = 0.000869


Can u explain to me how u did it?

 

[friction]

First one is
6C4 (1/2)^6 + 6C5 (1/2) ^6 + 6C6 (1/2)^6

X 100

that was probabilty of 4 even 5 even and 6 even times number of roles

second one you would do the same.

Good i hope its binomial probabilty not normal probaility.

 

[kooltrainer]

What about B?? its a diff one

 

[friction]

4C3 1/15 ^3 x (8/10 x 14/15)

 

[kooltrainer]

sorry , could you explain how??

oh, and u've got the wrong answer btw..

 

[lelouch]

[4C3 x (1/15)^3 x (14/15)^1 ] + [4C4 x (1/15)^4