A shopkeeper buys some fruits at a discount of 10% on the marked price. For selling the item he increases the marked price. If he wants to get a profit of 25% after allowing a discount of 15%, then by what percentage should his marked price be greater than the original marked price? (Correct to a nearest whole number)

Solution : 

We know Formula 

Cp/mp=100-d%/100+p%

So, cp/mp = 100-10%/100-x% 

Also , cp/mp = 100-15%/100+25% = 85/125 = 17/25 

Now comparing we have,  17/25 = 90/100-x

So, x=32% Approx

You can direct x and after getting value of x

 subtract by 100 

17/25 = 90/x , x= 132 or p%=32%  Ans.