Three coins are tossed. Find the chance of tossing: i) one heads and two tails ii) exactly two heads iii) at least two tails iv) no heads

Respuesta :

Answer:

i)

The probability that getting one heads and two tails = 0.375 = 37.5%

ii)

The probability that getting Exactly two heads = 0.375 = 37.5%

iii)

The probability that getting at -least two tails = 0.5 =50%

iv)

The probability that getting no heads = 0.125 = 12.5%

Step-by-step explanation:

Explanation:-

Given Three coins are tossed

The number of exhaustive cases

                = { HHH,TTT,HTT,THT,TTH,HTH,THH,HHT} =8

    n(S) = 8

i)

Let 'E₁' be the event of getting one heads and two tails

   n ( E₁) = {HTT ,THT , TTH} = 3

The probability that getting one heads and two tails

[tex]P(E_{1} ) = \frac{n(E_{1} )}{n(S)} = \frac{3}{8} = 0.375[/tex]

The chance of tossing one heads and two tails   = 37.5%

ii)

Let 'E₂' be the event of getting Exactly two heads

n(E₂) = {HTH,THH,HHT} =3

The probability that getting Exactly two heads

[tex]P(E_{2} ) = \frac{n(E_{2} )}{n(S)} = \frac{3}{8} = 0.375[/tex]

The chance of tossing Exactly two heads = 37.5%

iii)

Let 'E₃' be the event of getting at -least two tails

n(E₃) = {TTT,HTT,THT,TTH} = 4

The probability that getting at -least two tails

[tex]P(E_{3} ) = \frac{n(E_{3} )}{n(S)} = \frac{4}{8} = 0.5[/tex]

The chance of tossing at -least two tails = 50%

iv)

Let 'E₄' be the event of getting no heads

n(E₄) = { TTTT} =1

The probability that getting no heads

[tex]P(E_{4} ) = \frac{n(E_{4} )}{n(S)} = \frac{1}{8} = 0.125[/tex]

The chance of tossing no heads = 12.5%

Answer:

“If three coins are tossed, what is the probability of getting two heads and one tail?”

You can calculate it, but for such a small number of possible combinations of independent events (8), let’s look at them all.

H = heads

T = tails

Possible events with equal probability (order matters):

HHH

HHT

HTH

HTT

THH

THT

TTH

TTT

Number with 2 heads: 3

Total number: 8

From the definition of probability, the number you are looking for is 3/8 = 0.375 = 37.5%

Step-by-step explanation: