Jee Main
Probability
JEE Main 2025 (Online) 7th April Evening Shift
MCQ+4 / -12025
A bag contains 19 unbiased coins and one coin with head on both sides. One coin drawn at random is tossed and head turns up. If the probability that the drawn coin was unbiased, is $\frac{m}{n}$, $\gcd(m, n) = 1$, then $n^2 - m^2$ is equal to :