Okay, first of all, there's something called spaces like what I'm using right now. It's that big rectangular button at the bottom of your keyboard.
Second of all, I think the question is asking "A $300 mountainbike is discounted by 30% and then discounted an additional 10% for shoppers who arrive before 5:00a.m. Find the sales price of the bicycle."
$300*(100%-30%) = $210.
$210*(100%-10%) = $189
The answer is $189.