Question

On the situation where taking the numbers 123456 how many numbers can u form using 3 digits with no numbers repeated is that a permutation or combination?

Answer 1

Combination followed by permutation: `6C_3 X 3P_3=120`

Explanation:

Selection of 3 from 6 can be done in `6C_3=(6X5X4)/(1X2X3)=20` ways.

From each selection of 3 distinct digits, the digits can be

arranged, differently, in `3P_3 = 3X2X1= 6` ways.

So, the number of 3-git numbers formed = the product

20X6=120.