An unfair coin has a probability 0.6 of landing heads. The coin is tossed four times. What is the probability that it lands heads at least once?
A) 0.25
B) 0.9744
C) 0.8704
D) 0.784

Question

Quizplus · Accepted Answer

The easiest way to solve this problem is to calculate the probability of the coin never landing heads (i.e., landing tails every time) and subtracting that from 1. The probability of landing tails on a single toss is 1 - 0.6 = 0.4. For four tosses, the probability of all tails is $0.4^4 = 0.0256$. Therefore, the probability of getting at least one head is $1 - 0.0256 = 0.9744$.

An Unfair Coin Has a Probability 0