[ { "min_n": 2, "max_n": 10, "problem_prob": 0.5 }, { "min_n": 3, "max_n": 15, "problem_prob": 0.7 }, { "min_n": 2, "max_n": 8, "problem_prob": 0.6 }, { "min_n": 4, "max_n": 12, "problem_prob": 0.4 } ]