The explanations should be evident by careful consideration of the answers.I need serious help with these ten problems...someone please help me!! :/
1.) What is the probability of a person getting at least one question right on a multiple choice test with 10 questions (choices A-D for each question), if they guess at all of the questions?
Mr F says: 1 - Pr(get none right).
2.) The daily number is a 3 digit number ranging from 000-999, and each of the three digits is drawn from a bin with digits 0-9.
a.) What is the probability of getting at least one of the numbers right?
b.) What is the odd against getting at least one of the numbers right?
Mr F says: This makes no sense to me as written. Do you mean correctly guessing one of the numbers in the three digit number? In its correct position?
3.) There are 5 senators and 3 representatives to form a 4 person committee. What is the probability that there will be the same number of senators and representatives?
Mr F says: .
4.) If a person is dealt a 5 card hand from a standard deck of playing cards, what is the probability that the person is dealth a pair ( 2 cards of the same rankL 2's, 3's, 4'w, ...)?
Mr F say: Suppose the pair is 2 Kings. The Kings can be chosen in ways.
But the actual face value of the pair can be chosen in 13 ways.
And now you need to choose 3 more cards, none of which match each other. So choose 3 cards out of the 12 remaining values: ways.
But each card can be 1 of the 4 suits, and so there are (4)(4)(4) = 64 ways to choose the suits.
Therefore the total number of ways is (6)(13)(220)(64).
Divide by to get the probability.
5.) On hundred students were surveyed, and 25% said they like math, 45% said they like english, and 5% said they like both math and english. IF a students is randomly surveyed what is the probability that they student does not like math or english?
Mr F says: Pretend there's 100 students and draw a Venn Diagram.
6.) A shipment of ten calculators contains two defective ones. If you randomly choose four calculators, what is the probability that exactly one will be defective?
Mr F says: .
7.) A nickel, dime, and a quarter are tossed. What is the probability that the nickel and dime will show heads and the quarter will show tails?
Mr F says: Obviously Pr(HHT) = (1/2)(1/2)(1/2).
8.) Which has a greater probability: drawing an ace and a ten card (ten, jack, queen, or king) from a regular deck of 52 cards, or drawing an ace and ten card from two decks of regular playing cards?
Mr F says: 20/52 versus 40/104 ....
9.) What is the probability of being dealth an ace and a king if you are dealt two cards from a standard deck of cards?
Mr F says: Pr(AK) + Pr(KA) = (4/52)(4/51) + (4/52)(4/51) = ....
10.) What is the probability of guessing someone's MAC pin number if you know the first two digits of the four digit pin number (assume the pin number is random)?
Mr F says: (1/10)(1/10) = ....
PLEASE HELP ME...IT'S SO URGENT! THANKS!