A box has 9 red cards, 6 white cards and 2 blue cards. How many selections of 2 cards can be made so that (a) both cards are red and (b) none is red?
-
there are 9 red & 8 non-red cards
a. 9c2 = 36 <-----
b. 8c2 = 28 <----
this is a pretty basic q !
a. 9c2 = 36 <-----
b. 8c2 = 28 <----
this is a pretty basic q !