A Salesperson is paid 6% commission. How much does she sell to make $800?

The commission the sales person gets =
6%.

To determine the sale for which the sales person eans
$800.

We know that for every dollar of earning, the
salesperson should sell 100/6 dollars of sale.

Therefore to
earn $800 , he should sell  800* 100/6 =  80000/6 dollars of sale. This works out 
$13333.33 or more worth sale the salesperson has to do in order that he should earn a
commision of %800.

So the round figeure of the sale is
$13334 to earn
%8000.

Tally:

sale = $13334.
Commission aT 6% = 13334*0.6 = $800.4.

Sale = 13333.
commission = 13333*0.06 = $799.98, which less than $800.