We will have at first the 30% of the regular price to find the selling price
Since the regular price = $400
Then 30% of 400 is
[tex]\frac{30}{100}\times400=120[/tex]Subtract it from $400 to find the selling price
The selling price = 400 - 120 = $280
Now we will find 10% of $280 to get the final price
Since 10% of 280 is
[tex]\frac{10}{100}\times280=28[/tex]Subtract it from 280 to get the final price
The final price = 280 - 28 = $252
She can buy it for $252
The answer is D