Question

If you toss a coin 4 times, what's the probability that you'll get 3 heads?

Answer 1

think of all the possible arrangement that can occur when we toss a coin four time
HHHH
HHHT
HHTT
HTTT
TTTT
THHH
and so on

Answer 2

count all the possibilities and count how many of them are 3 heads

Answer 3

there is an easier way of doing this
but it is bit difficult to grasp why we are using the concept
so go with the basic idea of counting

Answer 4

Sir find probability just

Answer 5

I am basically not sure if it is correct!!!!!

Answer 6

1/2 is the probability

Answer 7

The probability of getting 3 heads and one tail in 4 tries is, by the Binomial Theorem
$$
{4\choose3}\left ({1\over2}\right )^3\left ({1\over2}\right)^1
$$

See - http://en.wikipedia.org/wiki/Binomial_distribution#Probability_mass_function

Answer 8

There are 2 * 2 * 2 * 2 = 16 total number of possible outcomes.

Of those, only the following 4 outcomes have exactly 3 heads.
HHHT
HHTH
HTHH
THHH

probability = (number of desired outcomes)/(total number of outcomes)