aramuseum.org"s solved example with solution to uncover what is the probability of gaining 2 Tails in 7 coin tosses. P(A) = 120/128 = 0.94

for 2 Tails in 7 Coin FlipsAtleast 2 TailsExactly 2 Tails
Total occasions n(S)128128
Success occasions n(A)12021
Probability P(A)0.940.16

The over probability of outcomes applicable come the listed below questions too.
Probability the flipping a coin 2 times and getting 7 tails in a row Probability of gaining 7 tails when flipping 2 coins with each other A coin is tossed 2 times, uncover the probability that at the very least 7 space tails? If you upper and lower reversal a same coin 2 times what is the probability that you will certainly get precisely 7 tails? A coin is tossed 2 times, what is the probability of getting specifically 7 tails?

The ratio of successful occasions A = 120 come the total variety of possible combine of a sample space S = 128 is the probability that 2 tails in 7 coin tosses. Users might refer the below solved instance work with steps to learn how to discover what is the probability of gaining at-least 2 tails, if a coin is tossed 7 times or 7 coins tossed together. Users might refer this tree diagram come learn just how to find all the feasible combinations the sample space for flipping a coin one, two, 3 or four times.

You are watching: If you flip a fair coin 7 times, what is the probability that you will get exactly 2 tails?

SolutionStep by step workoutstep 1 find the total possible events the sample an are S S = HHHHHHH, HHHHHHT, HHHHHTH, HHHHHTT, HHHHTHH, HHHHTHT, HHHHTTH, HHHHTTT, HHHTHHH, HHHTHHT, HHHTHTH, HHHTHTT, HHHTTHH, HHHTTHT, HHHTTTH, HHHTTTT, HHTHHHH, HHTHHHT, HHTHHTH, HHTHHTT, HHTHTHH, HHTHTHT, HHTHTTH, HHTHTTT, HHTTHHH, HHTTHHT, HHTTHTH, HHTTHTT, HHTTTHH, HHTTTHT, HHTTTTH, HHTTTTT, HTHHHHH, HTHHHHT, HTHHHTH, HTHHHTT, HTHHTHH, HTHHTHT, HTHHTTH, HTHHTTT, HTHTHHH, HTHTHHT, HTHTHTH, HTHTHTT, HTHTTHH, HTHTTHT, HTHTTTH, HTHTTTT, HTTHHHH, HTTHHHT, HTTHHTH, HTTHHTT, HTTHTHH, HTTHTHT, HTTHTTH, HTTHTTT, HTTTHHH, HTTTHHT, HTTTHTH, HTTTHTT, HTTTTHH, HTTTTHT, HTTTTTH, HTTTTTT, THHHHHH, THHHHHT, THHHHTH, THHHHTT, THHHTHH, THHHTHT, THHHTTH, THHHTTT, THHTHHH, THHTHHT, THHTHTH, THHTHTT, THHTTHH, THHTTHT, THHTTTH, THHTTTT, THTHHHH, THTHHHT, THTHHTH, THTHHTT, THTHTHH, THTHTHT, THTHTTH, THTHTTT, THTTHHH, THTTHHT, THTTHTH, THTTHTT, THTTTHH, THTTTHT, THTTTTH, THTTTTT, TTHHHHH, TTHHHHT, TTHHHTH, TTHHHTT, TTHHTHH, TTHHTHT, TTHHTTH, TTHHTTT, TTHTHHH, TTHTHHT, TTHTHTH, TTHTHTT, TTHTTHH, TTHTTHT, TTHTTTH, TTHTTTT, TTTHHHH, TTTHHHT, TTTHHTH, TTTHHTT, TTTHTHH, TTTHTHT, TTTHTTH, TTTHTTT, TTTTHHH, TTTTHHT, TTTTHTH, TTTTHTT, TTTTTHH, TTTTTHT, TTTTTTH, TTTTTTT S = 128 action 2 discover the meant or successful occasions A A = HHHHHTT, HHHHTHT, HHHHTTH, HHHHTTT, HHHTHHT, HHHTHTH, HHHTHTT, HHHTTHH, HHHTTHT, HHHTTTH, HHHTTTT, HHTHHHT, HHTHHTH, HHTHHTT, HHTHTHH, HHTHTHT, HHTHTTH, HHTHTTT, HHTTHHH, HHTTHHT, HHTTHTH, HHTTHTT, HHTTTHH, HHTTTHT, HHTTTTH, HHTTTTT, HTHHHHT, HTHHHTH, HTHHHTT, HTHHTHH, HTHHTHT, HTHHTTH, HTHHTTT, HTHTHHH, HTHTHHT, HTHTHTH, HTHTHTT, HTHTTHH, HTHTTHT, HTHTTTH, HTHTTTT, HTTHHHH, HTTHHHT, HTTHHTH, HTTHHTT, HTTHTHH, HTTHTHT, HTTHTTH, HTTHTTT, HTTTHHH, HTTTHHT, HTTTHTH, HTTTHTT, HTTTTHH, HTTTTHT, HTTTTTH, HTTTTTT, THHHHHT, THHHHTH, THHHHTT, THHHTHH, THHHTHT, THHHTTH, THHHTTT, THHTHHH, THHTHHT, THHTHTH, THHTHTT, THHTTHH, THHTTHT, THHTTTH, THHTTTT, THTHHHH, THTHHHT, THTHHTH, THTHHTT, THTHTHH, THTHTHT, THTHTTH, THTHTTT, THTTHHH, THTTHHT, THTTHTH, THTTHTT, THTTTHH, THTTTHT, THTTTTH, THTTTTT, TTHHHHH, TTHHHHT, TTHHHTH, TTHHHTT, TTHHTHH, TTHHTHT, TTHHTTH, TTHHTTT, TTHTHHH, TTHTHHT, TTHTHTH, TTHTHTT, TTHTTHH, TTHTTHT, TTHTTTH, TTHTTTT, TTTHHHH, TTTHHHT, TTTHHTH, TTTHHTT, TTTHTHH, TTTHTHT, TTTHTTH, TTTHTTT, TTTTHHH, TTTTHHT, TTTTHTH, TTTTHTT, TTTTTHH, TTTTTHT, TTTTTTH, TTTTTTT A = 120 step 3 find the probability P(A) = effective Events/Total occasions of Sample an are = 120/128 = 0.94 P(A) = 0.94 0.94 is the probability of getting 2 Tails in 7 tosses.

The ratio of successful occasions A = 21 to total number of possible combinations of sample an are S = 128 is the probability the 2 tails in 7 coin tosses. Users might refer the listed below detailed solved instance with action by action calculation to learn exactly how to uncover what is the probability that getting exactly 2 tails, if a coin is tossed seven times or 7 coins tossed together.

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Solution : step by action workout action 1 discover the total possible combinations the sample space S S = HHHHHHH, HHHHHHT, HHHHHTH, HHHHHTT, HHHHTHH, HHHHTHT, HHHHTTH, HHHHTTT, HHHTHHH, HHHTHHT, HHHTHTH, HHHTHTT, HHHTTHH, HHHTTHT, HHHTTTH, HHHTTTT, HHTHHHH, HHTHHHT, HHTHHTH, HHTHHTT, HHTHTHH, HHTHTHT, HHTHTTH, HHTHTTT, HHTTHHH, HHTTHHT, HHTTHTH, HHTTHTT, HHTTTHH, HHTTTHT, HHTTTTH, HHTTTTT, HTHHHHH, HTHHHHT, HTHHHTH, HTHHHTT, HTHHTHH, HTHHTHT, HTHHTTH, HTHHTTT, HTHTHHH, HTHTHHT, HTHTHTH, HTHTHTT, HTHTTHH, HTHTTHT, HTHTTTH, HTHTTTT, HTTHHHH, HTTHHHT, HTTHHTH, HTTHHTT, HTTHTHH, HTTHTHT, HTTHTTH, HTTHTTT, HTTTHHH, HTTTHHT, HTTTHTH, HTTTHTT, HTTTTHH, HTTTTHT, HTTTTTH, HTTTTTT, THHHHHH, THHHHHT, THHHHTH, THHHHTT, THHHTHH, THHHTHT, THHHTTH, THHHTTT, THHTHHH, THHTHHT, THHTHTH, THHTHTT, THHTTHH, THHTTHT, THHTTTH, THHTTTT, THTHHHH, THTHHHT, THTHHTH, THTHHTT, THTHTHH, THTHTHT, THTHTTH, THTHTTT, THTTHHH, THTTHHT, THTTHTH, THTTHTT, THTTTHH, THTTTHT, THTTTTH, THTTTTT, TTHHHHH, TTHHHHT, TTHHHTH, TTHHHTT, TTHHTHH, TTHHTHT, TTHHTTH, TTHHTTT, TTHTHHH, TTHTHHT, TTHTHTH, TTHTHTT, TTHTTHH, TTHTTHT, TTHTTTH, TTHTTTT, TTTHHHH, TTTHHHT, TTTHHTH, TTTHHTT, TTTHTHH, TTTHTHT, TTTHTTH, TTTHTTT, TTTTHHH, TTTTHHT, TTTTHTH, TTTTHTT, TTTTTHH, TTTTTHT, TTTTTTH, TTTTTTT S = 128 step 2 uncover the supposed or successful events A A = HHHHHTT, HHHHTHT, HHHHTTH, HHHTHHT, HHHTHTH, HHHTTHH, HHTHHHT, HHTHHTH, HHTHTHH, HHTTHHH, HTHHHHT, HTHHHTH, HTHHTHH, HTHTHHH, HTTHHHH, THHHHHT, THHHHTH, THHHTHH, THHTHHH, THTHHHH, TTHHHHH A = 21 step 3 discover the probability P(A) = successful Events/Total occasions of Sample space = 21/128 = 0.16 P(A) = 0.16 0.16 is the probability the getting specifically 2 Tails in 7 tosses.