# Aptitude | Probability | Question 1

Given a coin which gives HEADS with probability 1/4 and TAILS with 3/4. The coin is tossed k times. What is the probability that we get at least k/2 HEADS is less than or equal to?**(A)** (1/2) ^{k/5}**(B)** (1/2) ^{k/2}**(C)** (1/3) ^{k/2}**(D)** (1/5) ^{k/2}**Answer:** **(A)****Explanation:**

Source: http://www.cse.iitk.ac.in/users/sbaswana/CS648/Lecture-2-CS648.pptx

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