Question

Four coins are tossed together. What is the probability that head will appear on at least one of the four?

• A. $\frac{15}{16}$
• B. $\frac{1}{16}$
• C. $\frac{1}{4}$
• D. None of these
  

Answer 1

The correct option is A $\frac{15}{16}$

Probability of getting head if one coin is tossed is $p=\frac{1}{2}$
Here 4 coin are tossed together i.e $n=4$
Hence using binomial distribution,
Probability that head will appear at least of the four is $=1-P(X=0)=1{-}^4{C}_0{\left(\frac{1}{2}\right)}^4=1-\frac{1}{16}=\frac{15}{16}$