probability that a 4 is rolled --> 1/7 or 1 to 7 or 1:7 (all mean the same)
probability that about odd number is rolled --> 4/7 or 4 to 7 or 4:7 (all mean the same) you find this answer but counting how many odd numbers are in the number set 1,2,3,4,5,6,7 and set it proportional to 7 (the total amount of numbers)
