When a watch is sold at $$\frac{7}{8}$$ th of the marked price, there is a profit of 25%. At what percentage more than the cost price has the marked price of the watch been fixed? [Give your answer correct to 2 decimal places.]

Let's assume the marked price of the watch is 8y.

When a watch is sold at $$\frac{7}{8}$$ th of the marked price, there is a profit of 25%.

selling price of watch = $$\frac{7}{8}\times8y$$ = 7y

cost price of watch = $$\frac{7y}{\left(100+25\right)}\times\ 100$$

= $$\frac{7y}{125}\times\ 100$$

= $$\frac{7y}{5}\times\ 4$$

= $$\frac{28y}{5}$$

= 5.6y

Percentage change from cost price to marked price = $$\frac{8y-5.6y}{5.6y}\times\ 100$$

= $$\frac{2.4y}{5.6y}\times\ 100$$

= 42.86%

42.86% more than the cost price has the marked price of the watch been fixed.