For how many ordered pairs of positive integers n and k with n and k less than or equal to 20, is the number

((2n)!(2k)!) / (n!k!(n+k)!) an integer?

3 answers

yr pls someone solve it.....
No-one will solve it for you you cheat!!! Copying questions from Brilliant huh? Lame, lame!!!
so whats ur problem i mean usmey aapko problem kya hai..?