Answer :

Since there was a 10% discount, you know that 90% of the price is 76.50. So to get 100% of the price (the orginal price), you divide 76.50 by .9.
belcatya
make a proportion:
                         90% - 76.50$
 original price is 100% - x$

x=76.50$*100%/90%=85$
Answer: original price is 85$