An internent café charges $2.75 to use a computer and $.35 per minute while accessing the internet. what is the cost of using the internet for 28 minutes?

Internet + Computer = total cost

Using computer total charge is just $2.75
But using internet differs by min.
$.35 = 1 min
x = 28 min
Where x is the cost of internet usage in 28 min

(Cross Multiply)
.35 * 28 = x
x = 9.8
So the cost of using internet for 28 min is $9.80

Now for the total cost:
cost of using computer + cost of using internet for 28 min.

2.75 + 9.8 = $12.55