Question

The tree diagram below shows all of the possible outcomes for flipping three coins.

What is the probability that at least two of the coins will be tails?
1/8 3/8 1/2 3/4

Answer 1

The probability that two of the coins will be tails is 1/2

It is 1/2 because "at least two tails" means that two tails and the rest of the number of tails, which is 3. In total the three coins have 6 sides. The chance of having two tails and one is three out of 6, simplified is 1/2 ;)

Answer 2

Option C is correct.

Explanation:

From given tree Diagram.

Total No of Outcome = 8

Let E be the event in which atleast 2 coins shoes tails.

Favorable outcome = { (H,T,T) , (T,H,T) , (T,T,H) , (T,T,T) }

⇒ No. of favorable outcome = 4

`Probability\:of\:event\:E=(No\:of\:favorable\:outcome)/(Total\:no\:of\:outcome)`

`P(E)=(4)/(8)=(1)/(2)`

Therefore, Option C is correct.