Find the diameter of the circle with the given circumference

What is the probability of throwing several dice with sum equal to 6 (six)? show the ways of possibilities for sum 6 (as the numerator) and the ways of throwing n dices for n = 1, 2, 3, 4 or 5 as denominator for all the questions to earn full credits. (a)throw one die, (b) throw two dice, (c) throw three dice (d) throw 4 dice, (e) throw 5 dice

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

How do i simply this radical expression?