How many combinations of 6 numbers are there in 10 numbers?

The answer is 10!/[6!*(10-6)!] where n! represents 1*2*3*...*n

Number of combinations = 10*9*8*7*6*5*4*3*2*1/(6*5*4*3*2*1*4*3*2*1)

= 10*9*8*7/(4*3*2*1) = 210