Solution: The total number of days for which the record is available =250
(i) P (the forecast was correct on a given day)
= Total number of days for which the record is available  Number of days when the forecast was correct ​
=250175​=0.7
(ii) The number of days when the forecast was not correct =250−175=75
So, P( the forecast was not correct on a given day )=25075​=0.3
Notice that:
P (forecast was correct on a given day) +P (forecast was not correct on a given day)
=0.7+0.3=1