At a store everything is sold to 10% less than the price marked. If the owner buys a product for Rs. 90. What price should he mark them, if he wants to make a 10% profit on his cost?

At a store everything is sold to 10% less than the price marked. If the owner buys a product for Rs. 90. What price should he mark them, if he wants to make a 10% profit on his cost?

Explanation
Step 1: Let the marked price be Rs. x.

Since items are sold at 10% less than the marked price,
The selling price (SP) =

Step 2: Desired profit = 10% on cost

Cost price (CP) = Rs 90
Profit = 10% of 90 = Rs 9
So, desired Selling Price (SP) =Rs 90 + Rs9 = Rs 99

Step 3: Set up the equation

We already said that the selling price is 0.9x, so:

0.9x=990.9x = 99

Step 4: Solve for x

x=990.9=110x = frac{99}{0.9} = 110