Jane Street interview question

What is 87 x 46?

Interview Answers

Anonymous

10 Feb 2011

(90-3)*(50-4)= 4500-150-360+12= 4500-500-10+12=4002

2

Anonymous

1 May 2013

And this calculate from head?

2

Anonymous

17 July 2014

(87*50) - (87*4) This can be done without pen and paper.