The random variate X has the density f(x) = 0.4 - 0.08 x for 0 < x < 5 and 0 elsewhere.
a) Find the CDF and the inverse CDF of that random variate.
b) Write an R-function that generates random variates from that distribution.
c) Generate a sample of size n=7*10^5 using the function of b). Make a histogram of
that sample and add the plot of the density and check if your code is correct?