Answer:
D) 18
Explanation:
On Monday they sold 2 computers.
On Tuesday they sold 1 computer.
On Wednesday they sold 6 computers.
On Thursday they sold 9 computers.
The question is asking for the total number of computers sold, so add them all up:
2+1+6+9
=18
In total, 18 computers were sold.
Hope this helps! :)