Question

peter pays $85 for a watch after a discount of 20%. find the orginal price of the watch

Answer 1

Let $x be the original price of the watch. Then $(x-85) is the sum of a discount.

So we obtain the equation:

$x - 85 = 0.2 x; \newline x - 0.2x = 85; \newline 0.8x = 85; \newline x =\frac{85}{0.8}; \newline x = 106$

Thus, the original price of the watch is $106.