Question

flip a coin 10 times. find the probability of getting tails in the first four flips.

Answer 1

A coin flipping 10 times is same as 10 coins are tossed. So the sample sapce has outcomes.

So .

We want tails in first four flips. So the fifth flip can be either tails or heads. So the two sequeces are shown below.

a)

b)

So now for each six filps we can have heads or tails as the outcome . So such outcomes are possible.

Define event A as the first four flips are all tails thus ,.