The price of a cd on sale is 0.65c, where c is the original price of the cd. what does that mean?
the cd is on sale for 35% off.
the cd is on sale for 65% off.
the cd had an 35% tax added to it.
the cd was reduced by 65%.

Hey there!

If the price of a CD on sale is 0.65c, then 0.35 was taken off of the original price. You can find this if you subtract 0.65 from 1, or 65% from 100%. 

Your answer would not be your second option or your fourth option, since the price you're paying is 0.65 of the original price and you are getting 0.35 of the price off. Also, your third option wouldn't be correct either, since 0.35 isn't being added on top of the total price. 

Your answer is your first option. 

Hope this helped you out! :-)