Question 1083515
This is a combination of 13 things taken 4 at a time
C( 13, 4 ) = {{{ 13! / ( 4!*( 13 - 4 )! ) }}}
C( 13, 4 ) = {{{ 13! / ( 4!*9! ) }}}
C( 13,4 ) = {{{ ( 13*12*11*10 ) / ( 4*3*2*1 ) }}}
C( 13,4 ) = {{{ 17160 / 24 }}}
C( 13,4 ) = {{{ 715 }}}
There are 715 different 4-topping pizzas
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