Rand function that increment respectively

I want to generate random numbers

  randomnumberseed(M)=5 
    thenumberofrandomnumbersthatprogramshouldgenerate(N)=105 
    lowerbound(l)=-1
    upperbound(u)=20 and
    incrementrespectively(s)=0.01

srand(M);
for (i = 1; i <= N; i++) {
        rn = (l + (size) *(double)rand() / RAND_MAX);
        printf("%10.3f", rn);

So my random numbers must be like:

-0.460 12.930 16.550 12.490 2.600 19.300 7.270 7.490 0.720 10.400

8.140 9.210 8.330 5.760 3.260 0.070 13.630 11.070 15.500 11.310

And then i want to count the numbers which in the same interval(range will be divided 30 equal interval like (u-l)/30) and must to display.

First, i can generate random number between range but i can't provide incrementation respectively with s(0.01).

Secondly, how can i count intervals frequency? with an array or counter?

waiting for your urgent help :((((