Question

A coin is tossed 3 times in a row. What is the probability that heads appears on only the last toss.

Answer 1

HHH , HHT , HTH , THH , HTT , THT , TTH , TTT

I thought it was 3/8 but that was wrong.

Answer 2

First toss: P(tail) = 1/2
Second toss: P(tail) = 1/2
Last toss: P(head) = 1/2
The result of each toss is independent of the other results. Therefore the required probability is given by:
\[P(head\ only\ on\ last\ toss)=\frac{1}{2}\times\frac{1}{2}\times\frac{1}{2}=you\ can\ calculate\]

Answer 3

its 1/8 ☻☺