I think the answer is $1,033.50, because the total amount she paid, was the cost of the hat plus the sales tax. So, to find the total sales tax you multiply 975 and 0.06 (6% in decimal form) which is $58.50. Then you add $58.50 to $975, which gives you $1,033.50. --- Hope this helps.
It's basically 5,000*2=10,000 and 10,000/2=5,000. your answer would be either they multiplied 5,000 by 2 and 10,000 divided by 2, they increased the sales by 5,000