speed should be calculate in integer or double or float ? ??
Please tell me with reason thanks
Maths is Doctor that make our life easy ..
A float should be fine. I am assuming that speed is not an integer. A double is slower and uses more memory. But there might be spots where you need the extra precision. Basically you should be economical and use the smallest that you can.
In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.