Joe took a math test along with the rest of his class. The test contained 100 questions worth 1 point
each. The test scores were registered in a database. But, there was a glitch in the system and for
40% of the tests, the first digit of the test score was replaced by a 5. So, for example, if the test
score was 90, it would have been registered as 50 in the database if it had been affected by the system
glitch. We know that Joe answered at least 10 questions correctly. His score in the database is
registered as 55. If you were given a dollar for every question Joe answered correctly, how much
money statistically would you expect to have?
Do you have a suggestion
for this puzzle (e.g. something that should
be mentioned/clarified in the question or solution, bug, typo, etc.)?