Elaine is taking a test that has multiple choice questions,each with 4 answer choices. She comes to a question for which she doe

Question

2 years ago

15

s not know the awnser. If she can rule out three of the choices as wrong, by how much does she improve her probability of guessing correct awnser?

1 answer:

jekas [21] · Answer 1 · 2022-08-18T18:14:28+03:00

Assuming There is ONLY ONE CORRECT ANSWER,

The probability of her guessing the answer without ruling out the choices is 1/5.

if 3 choices are ruled out, then 1 out of the remaining two is right, which gives the probability 1/2

now, 1/5 = 20% , while 1/2 = 50%.

Therefore her probability of getting the correct answer improves by 30% [ not much in a REAL test though :P ]