Can someone answer these problems about probability?

1. You have a coin that is uniformly dense, perfectly flat and symmetrical, with two faces: a head and a tail. The experiment is to flip into the air and observe which face lands. Determine the following probabilities: (a) P(head) (b) P(tail) (c) P(head or tail)


2. What is the probability of getting a number greater than two in one roll of one die?


3. Find a probability of getting a sum of seven when a pair of dice is rolled?


4.What is the probability of getting a spade or club in picking a single card from the ordinary deck of playing cards? An ace or a diamond?


5. A loaded die is tossed 75 times and the face “6” appears 15 times in the 75 tosses, what is the probability that the face “6” will appear when this die is tossed?


6. In a high school graduating class of 100 students, 54 studied mathematics, 69 studied history, and 35 studied both mathematics and history. If one of these students is selected at random, find the probability that the student took history but not math?

Can someone answer these problems about probability?
1. (a) .5 (b) .5 (c) 1.0


2. 2/3


3. 1/6


4. Spade or club: 1/2 Ace or Diamond: 4/13


5. 1/5


6. 34/100
Reply:1. (a) 50% (b) 50% (c) 100%





2. 2/3 (66.7%)





3. sorry, i dont know =(, but i think the odds are 1/6? check other answers (if there are any) and compare, just in case)





4. 50% and 50%





5. 1/5 (20%)





6. i think 34% but i dont know
Reply:1(a). 1/2


(b). 1/2


(c). 1


2. 4/6 = 2/3


3. There are 6 ways to get a 7: 16,25,34,43,52,61. So the probability is 6/36 = 1/6


4. 1/2 for spade or club. For ace or diamond, there are 4 aces, and 13 diamonds, but 1 ace is a diamond, so there are a total of 16 "good" cards. So the probability is 16/52 = 4/13.


5. Well... we can only estimate the probability. But it's probably close to 15/75 = 1/5


6. 69-35 = 34 of them took history, but not math. So the probability is 34/100 = 17/50.