A salesperson is paid 3.5% commission. How much does she sell to make $450?

The sales person is getting a commission of 3.5%.
Thereore  she gets a commission of $3.5 for every $100 of sale. So to get a commission
of $1  she should make a sale amounting $100/3.5 = $28.5714
.

She got a commission of
$450.

Therefore to get a commission of $450 , she should
make a sale of  $450*28.5714 = $12857. 14

Therefore to get
$450 commission she should  sell  worth $12858 (rounded to next
integer).

To get a commission of  $1 she
sells