Question

I have a probablity question:
Suppose you draw a card from a well-shuffled deck of 52 cards. Find each of the following odds.
Odds against drawing a 3?
_:1
What are the odds of drawing a 3?
1:_
Odds against drawing a black 7?
_:1
Odds in favor of drawing a black 7?
1:_

Answer 1

well if you are only drawing one card, there are 52 cards in a deck, 13 of each suit (color), and 4 of each number...

thus...

Odds against drawing a 3?
- total amount of cards that AREN'T a 3 vs. the leftover cards that are a 3
=48 vs 4
= 12:1 odds

What are the odds of drawing a 3?
-Pretty much exact opposite of above
-Total amount of cards that ARE a 3, vs leftover cards that are...
-4 vs 48
-1:12 odds

Odds against drawing a black 7?
-Only 2 black sevens in a deck of 52. Thus...
-Total amount of cards that AREN'T black 7's, vs. are
-50 vs. 2
25:1 odds

Odds in favor of drawing a black 7?
1:25 lol