Question

Two coins are tossed simultaneously. Find the probability of getting at least one head.

Answer 1

S = {HH, HT, TH, TT}

n(S) = 4

A = {HH, HT, TH}

n(A) = 3

`P(A) = (n(A))/(n(S))`

= `3/4`

Answer 2

Given: Two fair coins are tossed simultaneously. Sample space S = {HH, HT, TH, TT} 4 equally likely outcomes.

Step-wise calculation:

1. “At least one head” outcomes = {HH, HT, TH} → count = 3.

2. Total outcomes = 4.

3. Probability = `3/4`. 

Alternatively P(at least one head) = 1 – P(no head)

= `1 - 1/4`

= `3/4`

P(at least one head) = `3/4`.