math
posted by Punkie .
Could someone please tell me if I am on track with my answer?
Jack is taking a fouritem truefalse test. He has no knowledge about the subject of the test and decides to flip a coin to answer the items. What is the probability that he receives a perfect score? What is the probability on a 10item test?
P(coin being correct in a 4 item t or f test) = 2/4
P(coin being correct in a 10 item t or f test) = 2/10 or 1/5

math 
Brittany
The chance that you get each question correct is 1/2. To calculate the probability of a perfect score on a 4 question test, you muliply the chance for each correct answer, sooo
1/2 X 1/2 X 1/2 X 1/2 = 1/16
On the 10 question test, it would be
1/2 X 1/2 X 1/2 X 1/2 X 1/2 X 1/2 X 1/2 X 1/2 X 1/2 X 1/2 = 1/1024 
math 
Punkie
Thank you, you really helped me!

math 
Brittany
Your very welcome!
Respond to this Question
Similar Questions

Math
Jack is taking a fouritem truefalse test. He has no knowledge about the subject of the test and decided to flip a coin to answer the items. What is the probability that he receives a perfect score? 
MATH Prob.
Jack is taking a fouritem trueâ€“false test. He has no knowledge about the subject of the test and decides to flip a coin to answer the items. What is the probability that he receives a perfect score? 
college math
Can someone just tell me the formula to use for this problem? 
MATH 157
Can anyone please help me understand these math problems. #4. How many threesymbol codes (letternumbernumber)can be made from the letters S, P, Y, and twodigits from the set of (0, 1, 2,..., 9) without repetition? 
Stats
A test has 15 true or false questions and 10 multiple choice questions (each with 4 choices). All questions are weighted equally. Jack has not studied at all for the test and randomly guesses. 1. What is the probability that Jack gets … 
tats
No(Did not lie) Yes(lied) positive test result 15(false positive) 42(true positive) negative test result 32(true negative) 9 (false negative) Refer to table and assume that one of the 98 test subjects is randomly selected. Find the … 
maths
Suppose a student guesses the answer to a true or false Question on a test by tossing a coin: if the coin lands Heads, she answers True, and if it lands Tails, she answers False. What is the chance that she gets the right answer? 
Math
On a truefalse test, each question has exactly one correct answer: true, or false. A student knows the correct answer to 70% of the questions on the test. Each of the remaining answers she guesses at random, independently of all other … 
Math (precelc 12)
A true false test has 15 questions. How many answer keys are possible of the answer to 6 of the questions is false and 9 are true? 
math
A truefalse test consists of 15 items. (b) What is the probability that Chris gets 80% or more for the test?