Question 159017
i got 8/30 as the probability.
here's how.
if the first one was 30, then the second one had to be 60, so the probability is 1/6 * 1/5 = 1/30.
if the first one was 40 then the second one could be 50 or 140, so the probability is 1/6 * 2/5 = 2/30.
if the first one was 50 then the second one could be 40 or 130, so the probability is 1/6 * 2/5 = 2/30.
if the first one was 60, then the second one had to be 30, so the probability is 1/6 * 1/5 = 1/30.
if the first one was 130, then the second one had to be 50, so the probability is 1/6 * 1/5 = 1/30.
if the first one was 140, then the second one had to be 40, so the probability is 1/6 * 1/5 = 1/30.
total probability came out to be 1/30 + 2/30 + 2/30 + 1/30 + 1/30 + 1/30 = 8/30.