Question 918989
Since order is important,  This is a permutation. 

With combination, order doesn't matter.  


The formula for permutation P =  n!/(n-r)!


In this case 

n = 10    the total #
r = 4     the selected number chosen to take out of the total

P = 10!/(10-4)! = (10*9*8*7*6*5*4*3*2*1)/6! 
           = (10*9*8*7*6*5*4*3*2*1)/(6*5*4*3*2*1) = 10*9*8*7
           = 5040