Answer:
a. 
b. 
c. 
d. 
Step-by-step explanation:
There are four desktop computers and two laptops.
On a specific day, we will set up 2 of these computers.
To find:
a. What is the probability that both selected computers are laptops?
b. What is the probability that both computers are desktops?
c. What is the probability that at least one computer is a desktop?
d. What is the probability that at least one of each type of computer is included?
Solution:
Using the probability formula for event E:

a. The number of successful outcomes for both computers being laptops =
= 1
Total possible outcomes = 15
The needed probability is
.
b. The successful outcomes for both being desktop computers = 
Total possible outcomes = 15
The required probability is
.
c. For at least one desktop:
Two scenarios exist:
1. 1 desktop and 1 laptop:
Successful outcomes = 
2. Both are desktops:
Successful outcomes = 
Total successful outcomes = 8 + 6 = 14
The needed probability is
.
d. 1 desktop and 1 laptop:
Successful outcomes = 
Total outcomes = 15
The required probability is
.