What is the original price if there is a 10% discount and the sale price is $76.50?

The sale price is $76.50 - this is 90% of the original price.
What you do next is find the unknown 10% discount value.
To do this you divide $76.50 by 9 to get 10%, the answer to that is $8.50
So now you know what the 10% was (i.e. $8.50), you add that value to the sale price.
If you do that you get the sum: $76.50 + $8.50
The answer is $85.00.

Hope it helped.

Is this hi is this a plato question