I'm posting one puzzle, riddle, math, or statistical problem a day. Try to answer each one and post your answers in the comments section. I'll post the answer the next day. Even if you have the same answer as someone else, feel free to put up your answer, too!
Tuesday, August 11, 2009
Thirty-two students took a nationwide exam and all the students from Indiana passed it. If the students from Indiana made up exactly 5% of the total number of students that passed the test, how many students passed it and how many students were from Indiana?
Subscribe to: Post Comments (Atom)
Total number who passed the exam is: 20ReplyDelete
Number of students from Indiana : 1
Trial and Error:
Assume 2 students from Indiana, then this 2 students are 5% of total passed, thus total number of students who passed should be 40. But this cannot be.
So now assume 1, then total students who passed is 20.
5% is 1/20, and the only multiple of 20 less than 32 is 20, so 20 students passed and only one of them is from Indiana.ReplyDelete
Well, that was quickly solved with limits. Just one student from Indiana (must have been a pretty limited 'nationwide' exam if only 32 people were tested).ReplyDelete