 Hello and welcome to the session. In this session we discussed the following question which says, a cell phone was marked at 20% above the cost price and a discount of 10% was given on its marked price. Find the gain or loss person made by the shopkeeper. First let's recall the formula for gain. Gain is equal to selling price S P minus the cost price C P then gain percent is equal to gain upon the cost price C P into 100% then discount is equal to discount percent of the marked price M P and selling price S P is equal to the marked price M P minus discount. This is the key idea to be used in this question. Now let's move on to the solution. We assume let the cost price C P be equal to rupees 100. Now as given in the question that the marked price of the C P is at 20% above the cost price. So then we have the marked price M P would be equal to rupees 120 since it's 20% above the cost price. Now we are given the discount percent as 10%. So now discount is equal to the discount percent that is 10% of the marked price M P. This is equal to 10 upon 100 into the marked price that is rupees 120 and this is equal to rupees 12. This is the discount given on the cell phone. So selling price is equal to M P that is the marked price minus discount from here we get selling price S P is equal to the marked price which is rupees 120 minus discount rupees 12 and this is equal to rupees 108. This is the selling price. Now you see that selling price is rupees 108 and the cost price is rupees 100. So selling price S P is more than the cost price C P. So we say that there is a gain and this gain is equal to selling price S P minus the cost price C P, which is equal to rupees 108 minus rupees 100 and this is equal to rupees 8 is the gain. Now next we find out the gain percent. This is equal to gain that is 8 upon the cost price which is 100 into 100% that is gain percent is equal to 8%. So final answer is 8%. So this completes the session. Hope you have understood the solutions for this question.