23.25 days (rounds to 23 days)
There are 31 days in October. First, you would change 75% into a decimal by moving the decimal point over two spaces:
75%=0.75
Then you would multiply 31 by .75 to find the number of days:
31×0.75=23.25
23.25 is the number of days it would be sunny; rounded down it would be 23 days total.