Suppose you had cancer and could roll a die, and if the die came up six, it would tell you with high certainty you had cancer, and if it came up as anything els

Suppose you had cancer and could roll a die, and if the die came up six, it would tell you with high certainty you had cancer, and if it came up as anything else, it would tell you nothing. If the test is very cheap, it’s probably a great test presuming you get to see the dice roll itself. The cost and invasiveness of the test is important.