A multiple choice exam is made up of 10 questions; Each question has 5 options and only one of them is correct. If a person answers at random, what is the probability of answering only 3 good questions?

Name: Solved: A multiple choice exam is made up of 10 questions; Each question has 5 options and only one of them is correct. If a person answers at random, what is the probability of answering only 3 good questions? - MathMaster
Brand: MathMaster
Rating: 4.9 (115 reviews)

115

likes

574 views

Answer to a math question A multiple choice exam is made up of 10 questions; Each question has 5 options and only one of them is correct. If a person answers at random, what is the probability of answering only 3 good questions?

$Expert avatar$

Hermann

4.6

126 Answers

Fórmula de probabilidad binomial P(X=k)=(n,k)*p^k * (1-p)^(nk) n=10 (10 preguntas) k=3 (3 respuestas correctas) p=1/5 (probabilidad de responder correctamente a una pregunta, ya que hay 5 opciones y solo una es correcta P(X=3)=(10,3)*(1/5)^3 * (4/5)^7 P(X=3)= (10!/3!7!)(1/5)^3 * (4/5)^7 = 0,201 Entonces, la probabilidad de responder correctamente sólo 3 preguntas es aproximadamente 0,201, o 20,1%.

Frequently asked questions (FAQs)

Which rule states that if two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the triangles are congruent?

What is the value of x in the equation log(x) = 2?

What is the measure of angle BAC if the angle bisector splits it into two congruent angles?

New questions in Mathematics

A particular employee arrives at work sometime between 8:00 a.m. and 8:50 a.m. Based on past experience the company has determined that the employee is equally likely to arrive at any time between 8:00 a.m. and 8:50 a.m. Find the probability that the employee will arrive between 8:05 a.m. and 8:40 a.m. Round your answer to four decimal places, if necessary.

Solution to the equation y'' - y' - 6y = 0

A book is between 400 and 450 pages. If we count them 2 at a time there is none left over, if we count them 5 at a time there is none left over and if we count them 7 at a time there are none left over, how many pages does the book have?

two particles start at the origin and move along the x axis. for 0 <= t <= 10, their respective position functions are given by x1 = cos(t) and x2 = (e^-3t) + 1. for how many values of t do the particles have the same velocity?

what is 3% of 105?

The director of a company must transfer 6 people from the human resources department to the sales department, in order to sustain sales during the month of December. What is the probability that he will transfer only 2 of them?

To make brine, José buys 1 kg of salt and pays 12 pesos. If he buys 4 kg, they charge him 48 pesos, but for 100 pesos they sell him 9 kg. What is the constant of proportionality?

Calculate the value of a so that the vectors (2,2,−1),(3,4,2) and(a,2,3) are coplanar.

In a laboratory test, it was found that a certain culture of bacteria develops in a favorable environment, doubling its population every 2 hours. The test started with a population of 100 bacteria. After six hours, it is estimated that the number of bacteria will be: