If a computer costs $1,200 and a printer costs $150, what is the total cost of both?

To determine the total cost of both the computer and the printer, you simply need to add their individual costs together. The computer costs $1,200 and the printer costs $150.

So, the calculation is as follows:

$1,200 (cost of the computer) + $150 (cost of the printer) = $1,350.

This sum represents the total expenditure required to purchase both items together. Thus, selecting the first option of $1,350 accurately reflects the correct total cost.