题目
A two-sided but very thick coin is expected to land on its edge twice out of every 100 flips. And the probability of face up (heads) and the probability of face down (tails) are equal. When the coin is flipped, the prize is $2 for heads, $4 for tails, and $50 when the coin lands on its edge. What is the expected value of the prize on a single coin toss?
选项
A.$3.94
B.$8.72
C.$11.50
D.$26.50
答案
A
解析
E = (50×2 + 49×2 + 49×4)/100 = 3.94E = (50×2 49×2 49×4)/100 = 3.94