need to write in python spyder

The binomial coefficient (?) is an integer equal to nx (n-1) x (n -2) x x (n -k+1) when k > 1, or (0) = 1 when k-0. a) Using this form for the binomial coefficient, write a user-defined function binomial(n,k) that calculates the binomial coefficient for given n and k. Make sure your function returns the answer in the form of an integer (not a float) and gives the correct value of 1 for the case where k0. b) Using your function write a program to print out the first 20 lines of "Pascal's triangle." The nth line of Pascal's triangle contains n +1 numbers, which are the coefficients (0), (1), and so on up to (z). Thus the first few lines are 121 1331 14641 c) The probability that an unbiased coin, tossed n times, will come up heads k times is ()/2". Write a program to calculate (a) the total probability that a coin tossed 100 times comes up heads exactly 60 times, and (b) the probability that it comes up heads 60 or more times