A store has 40 percent off sale on headphones with this discounted price of one pair of headphones is 36 dollars, what is the original price of pair of headphones?

Since there is a 40% discount, this means that they subtracted 40% of the original price from the original price, meaning that $36 is 60% of the original price. We can use ratios to figure out the original price (so 100% of the price).

100% x

60% 36

x = 36*100 / 60 = 3600 / 60 = 360 / 6 = 60

We can check this quickly: 60 * 0.4 (or 40%) is 24. If we subtract 60-24 we get 36, so we did the problem correctly