John tossed a fair coin 3 times. What is the probability that the coin landed heads up exactly twice?
Choices
A) 0.125
B) 0.175
C) 0.275
D) 0.375
E) 0.475
The probability is exactly same as the cion landed tail up once. That is 3*(1/2)^3 = 3/8 =0.375.   The answer is, therefore, (0.375).
<result>D</result>
John tossed a fair coin 3 times. What is the probability that the coin landed heads up exactly twice?