universety challenge

[kopend]

what was the tie break question

it was on monday or tueday this week

and the answer was -2

and if anyone can explain why

even better

[bibblebub]

Q: What is the determinant of a 2x2 matrix whose entries reading row by row are 2, 3, 4, 5 ?

A: -2

For a matrix

{a b
c d}

the determinant is ad - bc
and thus in this case 2x5 - 3x4 = 10 - 12 = -2

@27m30s http://www.bbc.co.uk/...2009_2010_Episode_32/

[another-view]

It was something along the lines of what would be the determinant of a 2 x 2 matrix with values 2,3,4,5. The answer was -2.

I guess you have to be studying maths to understand it.