PROBABILITY-

[adssaini]

Q. if the probability of rain on any given day is 50%, what it the probability that it rains exactly on 3 days in 5-day period.

Answer is 5/16

but I could not able to understand the a way solution is explained. Can anyone help me out ?

Thanks

[apoorva.srivastva]

[quote="adssaini"]Q. if the probability of rain on any given day is 50%, what it the probability that it rains exactly on 3 days in 5-day period.

Answer is 5/16

but I could not able to understand the a way solution is explained. Can anyone help me out ?

Thanks[/quote]

C(5,3) (.2)^3 * (.2)^2 = 5/16

[adssaini]

C(5,3) (.2)^3 * (.2)^2 = 5/16

Hi Apoorva,

Could you please explain this...I am not able to get this...

(.2)^3 * (.2)^2 = .00032

how you got 5/16 ?

thanks.

[apoorva.srivastva]

C(5,3) * (.2)^3 * (.2)^2 = .00032

C(5,3) = 10

so 10* * (.2)^3 * (.2)^2 = .00032

Please post questions in either PS forum or Ds forum....more ppl will be able to help u!!

[srisanj4]

Probability that it rains all 5 days = 1/2 * 1/2 * 1/2* 1/2 * 1/2

we need to find probability of raining exactly 3 days - in no particular order... which is 5 C 3 = 5*4*3/3*2*1 = 10

Probability of raining 3 days exact in 5 day period = 10 * 1/2^5 = 5/16