Question

Suppose you flip two coins. What is the probability of getting at most one heads? Give your answeras a reduced fraction.

Answer 1

At most one head mean:

0 head or 1 head

OR means "+" in probability.

Now,

0 head means 2 tails so the probability of 2 tails is:

1/2 * 1/2 = 1/4

Also,

1 head means :

1 tail and 1 heads

1/2 * 1/2 = 1/4

this can happen in 2 ways, so

Probabilty of 1 head = 2 * 1/4 = 1/2

Now, we add as said previously that "OR" means "+". So,

Answer is:

`(1)/(4)+(1)/(2)=(1)/(4)+(2)/(4)=(3)/(4)`

Answer as a reduced fraction IS 3/4