Question 700943

13.   {{{4!=4*3*2*1=24}}}  

14 {{{8!/(6!*2!)}}}...I guess you have this: {{{8!/ (6! 2!)=(8*7*6*5*4*3*2*1)/((6*5*4*3*2*1)(2*1))=40320/(720*2)=40320/1440=28}}}

15.   {{{6C3= 6!/((6-3)!*3!) =(6*5*4*3*2*1)/((3*2*1)(3*2*1))=720/(6*6)=720/36=20}}}

16.   {{{7P2= 7!/(7-2)!= 7!/5!=(7*6*5*4*3*2*1)/(5*4*3*2*1)=5040/120=42}}}