Question

You want to make five - letter codes that use the letters A, F ,E ,R and M without repeating any letter. What is the probability that a randomly chosen code starts with M and ends with E?

A) 0.01
B) 0.02
C) 0.05
D) 0.10

Answer 1

Any of the given 5 letters can be at the start of the code.

Total choices = 5

We want the code to start with A

Choices in favor = 1

Probability = favorable/total = 1/5 = 0.20

Answer 2

The correct answer option is C) 0.05

Explanation:

We are given five different alphabets A, F ,E ,R and M and with the help of these, we want to make five letter codes without repeating ant letter.

Since, each letter can be used once so the probability of picking a M first =
`(1)/(5)`.

Now we want the following sequence:

(not E, not E, not E) =
`(3)/(4) *(2)/(3) *(1)/(2)` =
`(1)/(4)`

So the probability that a randomly chosen code starts with M and ends with E =
`(1)/(5) *(1)/(4)` =
`(1)/(20) = 0.05`