 Hello and welcome to the session. I am Asha and I am going to help you with the following question that says the owner of a milk store finds that he can sell 980 litres of milk each week at rupees 14 per litre and 1220 litres of milk each week at rupees 16 per litres. Assuming a linear relationship between selling price and demand, how many litres could he sell weekly at rupees 17 per litre? Now begin with the solution and as we are given that there is a linear relationship between selling price and demand. So let us make a table. This is selling price in rupees, this is demand in litres. This is rupees 14 and the demand is 980 litres and when the selling price is rupees 16 and the demand is 1220 litres. Now let us denote this by x1, x2, y1 and y2 and p which is x1, y1 and q which is x2, y2. So this is given by y2 minus y1 upon x2 minus x1, this y2 is 1220 minus 980 upon 16 minus 14 and this is further equal to upon 2 which is equal to 120. Now equation of the line y1 or x2, y2, x1, y1 which is 14,908 having slope 120 is minus 14. This is further equal to into 120x minus 1680 minus y is equal to 1680 minus 980 or 120x minus y is equal to 700. So this is the equation of the line passing through the points p and q. Now the question further says how many litres could we sell weekly at rupees 17 per litre. So when the selling price is 17 we have to find the demand. Substituting this is equal to 17 and this equation we will get the value of y. So we have 120 into 17 minus y is equal to 700 or y is equal to 2040 minus 700 which is equal to 1340. Hence our answer is 1340 litres of milk he can sold 17 per litre. This completes the session. Hope you have understood it. Take care and have a good day.