sample.py

import random

def rand(low, up):
    if low < up:
        return rand(up, low)
    return low + random.random()*(up-low)

def sample(m, n):
    low = 1
    upper = m * 0.3

    remain = m
    result = []
    for i in range(n-1):
        remain_i = n - 1 - i
        l = max(low, remain - upper * remain_i)
        u = min(upper, remain - low * remain_i)
        x = rand(l, u)
        remain -= x
        result.append(x)
    result.append(remain)
    random.shuffle(result)
    return result

m = 3000
n = 10
s = 10000
result = [0]*10
for i in range(s):
    result[int(sample(m, n)[0]) * 100 // (3*m)] += 1
for i, v in enumerate(result):
    print(('%3d: %.2f ' % (i*3*m//100, v * 100 / s)) + '#' '#'*(v * 100 // s))