Bissoy.com
Doctors Medicines MCQs Q&A

Three coins are tossed together. Find the probability of getting:

(i) exactly two heads

(ii) at least two heads

(iii) at least one head and one tail

(iv) no tails

4 views

2 Answers

When 3 coins are tossed together,

Total no. of possible outcomes = 8 {HHH, HHT, HTH, HTT, THH,THT, TTH, TTT}

(i) Probability of an event = (No. of favorable outcomes)/(Total no. of possible outcomes)

Let E ⟶ event of getting exactly two heads

No. of favourable outcomes = 3 {HHT, HTH, THH}

Total no. of possible outcomes = 8

P(E) = 3/8

(ii) E ⟶ getting at least 2 Heads

No. of favourable outcomes = 4 {HHH, HHT, HTH, THH}

Total no. of possible outcomes = 8

P(E) = 4/8 = 1/2

(iii) E⟶ getting at least one Head & one Tail

No. of favourable outcomes = 6 {HHT, HTH, HTT, THH, THT, TTH}

Total no. of possible outcomes = 8

P(E) = 6/8 = 3/4

(iv) E ⟶ getting no tails

No. of favourable outcomes = 1 {HHH}

Total no. of possible outcomes = 8

P(E) = 1/8

4 views

(i) Exactly two heads

Possible outcome of tossing three coins are: HTT, HHT, HHH, HTH, TTT, TTH, THT, THH

Number of outcomes of exactly two heads are: 3

Probability of getting exactly two heads is = Total numbers/Total number of outcomes

= 3/8

∴ Probability of getting exactly two heads is 3/8

(ii) At least two heads

Possible outcome of tossing three coins are: HTT, HHT, HHH, HTH, TTT, TTH, THT, THH

Number of outcomes of at least two heads are: 4

Probability of getting at least two heads is = Total numbers/Total number of outcomes

= 4/8

= 1/2

∴ Probability of getting at least two heads is 1/2

(iii) At least one head and one tail

Possible outcome of tossing three coins are: HTT, HHT, HHH, HTH, TTT, TTH, THT, THH

Number of outcomes of at least one head and one tail are: 6

Probability of getting at least one head and one tail is = Total numbers/Total number of outcomes

= 6/8

= 3/4

∴ Probability of getting at least one head and one tail is 3/4

(iv) No tails

Possible outcome of tossing three coins are: HTT, HHT, HHH, HTH, TTT, TTH, THT, THH

Number of outcomes of no tails are: 1

Probability of getting no tails is = Total numbers/Total number of outcomes

= 1/8

∴ Probability of getting no tails is 1/8

4 views

Related Questions