12/5 - 3/10 = 24-3 /10 = 21/10
OR 2.1 in decimal form
You have to calculate how many ways you can select six things (r)
from a set of 9 things (n). (See attached formula).
9! / 6! * (3!) =
9*8*7 * 6! / 6! * 3! =
9*8*7 / 3! =
3 * 4 * 7 = 84 lineups
For this you have to get r by itself so you put 1 over 3 and move it to the other side and then you get 2/3 as an answer