VCE maths problem: Can you solve the 50 cent question?

It's the 50 cent question.

VCE Further Maths students have been debating one of the tougher questions in the subject's exam on Friday.

Here it is:

Teachers deny the question was too difficult (scroll to the bottom of the article for the solution).

But strong maths students made the mistake of overthinking the question, while weaker students froze up, believing there was not enough information to solve the question.

Exam students had to think logically, said Shelford Girls Grammar student Daphne Fourniotis.

"It was quite different to the ones we had been doing. I did find it challenging … under the stress of the exam. I found it a little ambiguous and confusing. I think I was over thinking it," said Daphne, who took the question home to check she got the answer right.

"You had to read between the lines and analyse the question, people would have jumped at that question too soon."

Students taking to social media didn't hide their frustration.

One student took it out on the rapper named 50 Cent, posting: "F*** You 50 Cent. I never liked your music anyway."

Others called out to their friends for answers on Facebook.

Sunshine College teacher Graeme Newman said the 50 cent question was challenging, but he believed the two parts of the exam, which were on Friday and Monday, were fair.

"Most exam questions try to give students a bit of a 'kick along' in terms of the way they set up the diagrams. They didn't do that in this question, they really needed to draw the triangles themselves and work it out from there."

But the trigonometry question was not the only puzzle confusing students.

In the days leading up to the Further Maths exam, the logistics of compiling a bound reference of notes (which are permitted in some exams including Further Maths) became a trending lamentation on VCE discussion forums.    

  Others, it appears, took liberties...   

The Victorian Curriculum and Assessment Authority (VCAA) has given clear guidelines on how students should bind their references for the exam.

"Binding can include glue, staple, spiral or comb binding," the authority states in guidelines for the students.

In all, maths teachers praised the Further Maths exam. Mount Scopus Memorial College maths teacher Esther Tan said the exam included questions that would have catered to stronger and weaker students.

Further Maths is the second most popular VCE subject, behind English, with 31,305 students enrolled at the start of the year.

Solution: 60 degrees.

Here's why:

In a six-sided figure, the exterior angle is 360/6 = 60 degrees.

In a 50 cent piece, there are 12 sides, so each exterior angle is 360/12 = 30 degrees.

The angle in the question is the sum of two exterior angles (one from each coin), so 2 x 30 = 60 degrees.

A reader explained this a different way: in walking all the way around a 12-sided shape, do 12 small turns to make up a 360 degree turn. So each turn is 360/12 = 30 degrees. The angle in question encompasses two "turns".

Another reader, Dr. Jahan Zahid, made a video on Monday to explain the sum.

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