If one considers each day independent of the day before (it is not),
pr(rainanyday)=5/7
Pr(rainonly one day)= 5/7 * 2/7 * 2ways
what can it happen on the weekend?
RR
RN
NR
NN
so of the possibilities, RN or nR are what we focus on.
Pr(rain only one day)=20/49
Lets check
Pr(rain both days)=25/49
pr(rain no days)=4/49
check: do these add to 1?
In a mountain village it rains on average 5 days a week. Find the probability that over a weekend it rains on exactly one of the two days.
1 answer
1 answer