Sunday, 15 June 2014

mathematics - A truly amazing way of making the number 2016




Find a mathematical expression that yields the value $2016$ while obeying the following rules:



  • Each of the digits $1,2,3,4,5,6,7,8,9$ is used exactly once

  • Decimal points are allowed

  • You may use brackets "(" and ")" to structure your expression, and to make it well-defined

  • The only allowed mathematical operations are addition (+), subtraction (-), multiplication (*) and division (÷)

  • The only allowed mathematical functions are square-roots and logarithms. Logarithms must be written in the form $\log[b](x)$ to denote the base-$b$ logarithm of number $x$





Note that in particular the following is not allowed:



  • Juxtaposition of digits (as juxtaposing 1 and 3 to get "31")

  • other mathematical operations and functions (cube-roots, exponentiation, factorials, absolute values, trigonometric functions, etc)

  • matrices and determinants

  • integration, differentiation, limits



Answer





$$\frac{9\cdot 8\cdot 7\cdot6\cdot 2}{3}+5-4-1$$



And three more à la Perry



$$1\cdot(2-3+4-5+6)\cdot7\cdot8\cdot 9$$
$$(1+2+3+4+5+6+7)\cdot8\cdot9$$
$$ 1\cdot(2+3+4+5)\cdot 6 \cdot(7+8+9)$$



No comments:

Post a Comment