Maths question from Panchayat Secretary (VLW) exam, 2025 by JKSSB
The probability of occurrence of heads on a biased coin is twice the probability of occurrence of tails. What is the probability of occurrence of tails when this coin is tossed?
Last updated Jun 13, 2026
Correct Answer:
Option B —
1/3
Step-by-Step Explanation
Step 1: Understand the total probability
When you toss a coin, there are only two possible outcomes: it must land on either heads or tails. Therefore, the probability of getting heads plus the probability of getting tails must always equal 1 (representing a one hundred percent certainty that one of the two will happen).
Step 2: Use the relationship between heads and tails
The problem states that the probability of getting heads is twice as much as the probability of getting tails.
Imagine dividing the total probability into equal parts or shares:
The probability of getting tails gets 1 share.
The probability of getting heads is twice that amount, so it gets 2 shares.
Step 3: Calculate the probability of tails
Together, the total number of shares is 3 (1 share for tails plus 2 shares for heads).
Since the total probability of 1 is split into 3 equal shares, each share is worth 1/3.
Because the occurrence of tails represents exactly 1 of those shares, the probability of getting tails is 1/3.
(Correspondingly, the probability of getting heads would be 2/3, which is exactly twice the probability of tails).
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
