CUET Preparation Today
The least number of times a fair coin be tossed so that the probability of having atleast one head is more than 80% is : |
2 5 3 4 |
3 |
The correct answer is Option (3) → 3 $\text{P(at least one head) = 1 - P(No heads)}$ $⇒1-(\frac{1}{2})^n>0.80$ $⇒(\frac{1}{2})^n<0.20$ $⇒n>2.32$ ∴ The least number of tosses required is 3. |
