In Rwanda, the chance for rain on any given day is 1/2. What is the probability that it rains on 5 out of 7 consecutive days in Rwanda?
Answers.
A) 4/7  B) 3/7  C) 21/128  D) 4/28  E) 28/135
using Binomial. theorem   n21/128r (p)^r (q)^n-r   721/1285 (1/2)^5 (1/2)^r   which is 21/128   Answer is 21/128.
<result>C</result>
In Rwanda, the chance for rain on any given day is 1/2. What is the probability that it rains on 5 out of 7 consecutive days in Rwanda?