I got that from my sister in US

At Duke University, there were four sophomores taking
>> Chemistry and all of them had an A so far.
>> These four friends were so confident that the weekend
>> before finals, they decided to visit some friends and
>> have big party. They had a great time, but after all
>> the hearty partying, they slept all day Sunday and
>> didn't make it back to Duke until early Monday
>> morning.
>>
>> Rather than taking the final then, they decided that
>> after the final, they would explain to their professor
>> why they missed it. They said that they visited
>> friends but on the way back, had a flat tire. As a
>> result, they missed the final.
>>
>> The professor agreed they could make up the final the
>> next day. The guys were excited and relieved. They
>> studied that night for the exam.
>>
>> He placed them in separate rooms and gave them a test
>> booklet. They quickly answered the first problem,
>> worth five points. Cool, they thought! Each one in
>> separate rooms thought this is going to be easy.
>>
>> Then they turned the page.
>> The second page was written:
>> ''For 95 points: Which tire?''
>>