JEE MainMathematicsProbabilityMCQ+4 / −1
Minimum number of times a fair coin must be tossed so that the probability of getting at least one head is more than 99% is :
- A6
- B5
- C8
- D7
View written solutionFree
Correct answer: D
-
Let the coin be tossed times.
-
We need:
-
Use the complement event:
For a fair coin, , so
Thus,
- Solve the inequality:
Now check powers of :
So is not enough, but works.
-
Therefore, the minimum number of tosses required is
-
Option check:
- A: ❌
- B: ❌
- C: ❌ (works, but not minimum)
- D: ✅
Hence, the correct option is .
Comparison with stored answer: Stored correct answer is , which matches our result.
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