A suit is on sale for $355, which is 29% less than the regular price

What is the question? I assume you want to find out what the original price is.

To find the original price you have to work backwards.

$355/.71 = $500 (original price)

To find out what the original price was you have to do the opposite. Normally, you multiply the original price by the percentage and then subtract.

But, to do this problem you have to subtract the percent from 100 then divide the sale price by that number.