Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
math
probability
| Question | Answer |
|---|---|
| and | multiply - |
| or | -add -separate choices |
| if you can only pick y things out of x options then | 1. write y blanks 2. start with x and count down until the blanks are filled 3. multiply the blanks |
| when given x things and asked how many ways to arrange them... If you are arranging all items: | take the factorial of x |
| permutations | group of elements with order -ORDER MATTERS |
| permutations formula If you are selecting and arranging only r items from n: | P(n, r) = n! / (n − r)! n = total number r = number you want to arrange |
| if one item must be in a specific placement, we cna still use it again for another place (we can use it more than once) so take that insto account | |
| xPx | x! |
| arranging letters ina word with repeats (how many arrangements) | total #s ----------------------------- number of times each things repeats (factorial of each and multiply) |
| combinations | order does not matter: key word: choose -if you have ABC, it is the same as BCA, that counts as the same group |
| combinations formula | nCr = n! / [r!(n − r)!] use the formula If you are selecting and arranging only r items from n |
| Girls: 8 Boys: 4 how many ways can you arrange 2 boys and 5 girls | 4C2 x 8C5 -solve each gender individually and then multiply becuase its boys AND girls |
| Girls: 8 Boys: 4 ways to arrange 4 boys in a care with 7 seats | zero -not enough boys |
| Girls: 8 Boys: 4 ways to arrange peter AND manual (2 of the boys) in a 7-seat car | 1C1 x 1C1 x 10C5 |
| how to find the probability of an event P(event) P(e) | # of outcomes of event ------------------------ total # of outcomes (s) OR # of favorable things ------------------------ total # -write answer as a fraction |
| the probability of any event is between... | 0-1 1 means the event will always occue 0 means the even will never occur |
| how many possibilities does 1 dice have | 6 |
| odds in favor of an event P(E | # of favorable event --------------------------- # of unfavorable events write aswer as a ratio numeratior : denom -the numerator and denom should add up to the total |
| odds against an event | # of unfavorale events --------------------------- # of favorable events |
| when asked to find the probability of sm, determine a condition | -any description that is used as a adjective is usually a condition -anything that comes after "given that" conditions do in teh demonominator of your ratio |
| how to know when to use and/or rules and when to use P or C | and/or = there is one group/ number, you are sellecting from one pool of numbers C or P = there are two numbers, you are making a group from another group |
| deck of cards | 52 cards total -13 hearts (red) -13 spades (black) -13 clover things (black) -13 diamonds (red) -in each suit, there are cards 2-10, 3 face cards, and one ace -THERE ARE NO 1 CARDS |
| are arranging books on a shlf p or c | Position 1, Position 2, Position 3 are different. If you swap two books, the shelf looks different. So order matters → Permutation |
| is selecting people from a group p or c | Alice, Bob, Charlie Is this different from: Charlie, Bob, Alice? No. It’s the same group. There are no positions like “first person”, “second person”. So order does NOT matter → Combination |
| selecting people for a team and each person has a different role | P Now suppose you choose: President Vice President Secretary Now positions exist. If Alice is President and Bob is VP that’s different from Bob is President and Alice is VP. |
| are arranging books on a shlf p or c | Position 1, Position 2, Position 3 are different. If you swap two books, the shelf looks different. So order matters → Permutation |
| arranging words is usually C or P | Changing the order changes the word. So forming words = Permutation. |
| is selecting people from a group p or c | Alice, Bob, Charlie Is this different from: Charlie, Bob, Alice? No. It’s the same group. There are no positions like “first person”, “second person”. So order does NOT matter → Combination |
| selecting people for a team and each person has a different role | P Now suppose you choose: President Vice President Secretary Now positions exist. If Alice is President and Bob is VP that’s different from Bob is President and Alice is VP. |
| arranging words is usually C or P | Changing the order changes the word. So forming words = Permutation. |
| permuations keywords | key words: assign or arrange, sequences,line up |
| combination keywords | groups, teams, comittees, choose |
| when you have two dice that are different colors, (3, 3) counts only once because both dice are showing the same number. (1, 5) and (5, 1) are two distinct outcomes. | |
| redo the money probability problem | |
| formatt differences for odds and probability | probability: written as a fraction odds: you use a : |
| number of arrangements of two dice when one is black and one is white | 36 |
Created by:
Blessed Rectangle 10