Question

Dear Brainly.com,

Answer 1

"of the computers" tells you that the answer is a percent of ALL of them.
How many computers are there altogether ?  (36 + 54) = 90 computers.

How many laptops are there ?  ===>  54

What percentage of the total of  90  is  54  ?

       54/90 = 0.6  =  60% .

Answer 2

First find the total number of computers 
which is 36+54= 90 total number of computers
use ratio and proportion
56/90= x/100
cross multiply
90x=5400
 x= 60% of the computers are laptops

hope this helps