Posted by Anonymous on Wednesday, June 27, 2012 at 1:15pm.
Sara tossed a fair coin five times, and Kaleb tossed a fair coin three times. There were five heads and three tails in the eight tosses. What is the probability that either Sara or Kaleb tossed exactly three heads? Express your answer as a common fraction.

common fraction  Count Iblis, Wednesday, June 27, 2012 at 4:23pm
Probability that Sarah throws exactly 3 heads:
Binomial[5,3] 2^(5) = 10/32 = 5/16
Probability that Sarah does not throw excatly 3 heads is:
1  5/16 = 11/16
Probability that Kaleb throws exactly 3 heads:
1/8
Probability that Kaleb does not throw excatly 3 heads is:
11/8 = 7/8
Probability that neither Kaleb nor Sarah throw exactly 3 heads is:
11/16 * 7/8 = 77/128
Probability that either Kaleb or Sarah throw exactly 3 heads is:
1  77/128 = 51/128
Answer This Question
Related Questions
 CALC  A biased coin whose chance of heads is 0.4 is tossed five times in a row...
 math  a fair coin is tossed in the air 4 times. if the coin lands heads up the ...
 math  Seth tossed a fair coin five times and got five heads. The probability ...
 Math  A biased coin is tossed 3 times. The probability that the coin will land ...
 Prealgebra/probability  A coin is tossed three times. Use a tree diagram to ...
 Math  Luis has a coin that is weighted so that the probability that Heads ...
 probability  if a fair coin is tossed 4 times, what is the probability of ...
 math  A fair coin is tossed 10 times. What is the probability of getting ...
 algebra 2  A fair coin is tossed 4 times. Given that each of the first 3 tosses...
 Data management  A coin was tossed 1000 times in an experiment to decide ...
More Related Questions