Question

There are20 keys on a keychain. One of the keys starts a car. If a key is randomly chosen what is the probability that it starts the car

A)5% B)25% C)20% D)15%

Answer 1

Considering the definition of probability, the probability that the key starts the car is 5%.

Definition of probability

Probability is the greater or lesser chance that a given event will occur.

In other words, the probability establishes a relationship between the number of favorable events and the total number of possible events.

Then, the probability of any event A is defined as the ratio between the number of favorable cases (number of cases in which event A may or may not occur) and the total number of possible cases. This is called Laplace's Law.

$P(A)=\frac{number of favorable cases}{number of possible cases}$

Probability that the key starts the car

In this case, you know:

Total number of keys in a key chain = 20 (number of possible cases)

The number of right key to start the car = 1 (number of favorable cases)

Replacing in the definition of probability:

$P(A)=\frac{1}{20}$

Solving:

P(A)= 0.05

Expressed as a percentage:

P(A)= 5%

Finally, the correct answer is option A): the probability that the key starts the car is 5%.

Learn more about probability:

https://brainly.com/question/3283947