Mr Boh Tak Chek is a terminal stage LMBFH Syndrome sufferer.
His teachers have given up on him. His loved ones have been told he has at most “three more weeks”, and were advised to make the necessary arrangements to keep his spirits up in the last leg of his academic life.
As Mr Boh wheeled himself into an exam hall to take the Paper 1 of a Mathematics subject on a gloomy Monday afternoon, he thought about the countless lessons he pon-ed, the endless Maple Story hours, the hundreds of late-night football matches, the Joss Sticks sessions he didn’t sign up …
But it’s now too late. A sudden inability to recall yet another formula (just memorized an hour ago) reminded him of his status in the final throes of this terrifying disease.
Only a miracle can save Mr Boh now.
The Mathematics paper contains 12 different questions of which 3 are on trigonometry, 4 are on algebra and 5 are on calculus. Ravaged by LMBFH Syndrome, Mr Boh is too weak to answer all and only has enough time to do 8 questions.
- Calculate the number of different ways in which he can select 8 questions if there is no restriction.
- Unfortunately Mr Boh did not revise one of the topics. Calculate the number of these selections which contain questions on only 2 of the 3 topics.
On the following day, Mr Boh wheeled himself again into the exam hall to take Paper II of this Mathematics subject. This time, to his horror, all 12 questions look alien to him!
As such he is leaving everything to fate as to the order of the questions to attempt:
The 12 questions are labeled A–L. As per Paper 1, Mr Boh only has time to do 8 questions.
- Calculate the number of possible arrangements of 8 questions chosen from the 12.
- Mr Boh thinks Question A looks familiar. Calculate the number of these arrangements in which Question A is appears as the first question.
- Calculate the number of these arrangements which contain Question A.
Students, do not be become another Mr Boh. The Last-Minute Buddha Foot Hugging Syndrome can be cured. If you’re taking your O-Levels in 2008 or beyond, please contact Miss Loi today to begin a healthy lifestyle of regular Joss Sticks sessions.
Remember, Early Detection Saves Your Academic Life.
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