Lyn, if I add 8% of an amount to the amount, I now have 108% of the original amount, right?
Let's look. 8% of 200 is 16. Since 200 is 100% of 200, and I am adding 8% of 200, 216 is 108% of 200. 200(1.08) = 216
Now, if I take 8% away from an amount, I'm left with 92% of the amount. Like the problem, if I take 92% of 216, I'm left with 198.72. 216(.92) = 198.72
If I add 8% and take away 8%, shouldn't I be back to where I started? No, because 8% of the larger amount is more than 8% of the original amount!
Back to the problem. We want 92% of 108% of 17.50
.92(1.08)(17.5) = $17.39
Hope this helps!