Homework Help: common fraction

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:

1-1/8 = 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

math - Seth tossed a fair coin five times and got five heads. The probability ...
CALC - A biased coin whose chance of heads is 0.4 is tossed five times in a row...
Statistics - A fair coin is tossed seven times. what is the probability of ...
probability - if a fair coin is tossed 4 times, what is the probability of ...
Math - Would you be more likely to get at least 70% tails if you flip a fair ...
math - if a fair coin is tossed 3 times, what is the probability of getting 3 ...
Data management - A coin was tossed 1000 times in an experiment to decide ...
Data Management Help! - A coin was tossed 1000 times in an experiment to decide ...
maths - A coin is biased so that a head is twicw as likely to occur as a tail. ...
TEST TOMM. NEED HELP IMMEDIATELY. PROBABILITY - A fair coin is tossed ten times ...

For Further Reading

First Name:
School Subject:
Answer: