A computer table, 4 bar stools and a cabinet costs a total of $352. Each bar stool costs 1/5 as much as the computer table. The cabinet costs $40 less than the table. a)How much is the computer table

b)What is the difference in the cost between the cabinet and 1 bar stool?

Here we see that all the prices are related to the computer table, so let's express all costs in terms of the computer table.

A bar stool costs (1/5) of a computer table, so 4 cost 4(1/5)=4/5 of a computer table.
A cabinet costs $40 less than a computer table.

So
1 computer table + (4/5) of a computer table and (computer table less $40) = $352
If we put up $40 more, we can change the cabinet for a computer table, or
2 4/5 computer tables cost $352+40=392
Each computer table costs therefore
$392/(2 4/5) = $392*(5/14)= $140.

Now all the rest can be solved be the aforementioned rules.