 Hi and welcome to the session. Let us discuss the following question. The question says, a bus stop is varicated from the remaining part of the road by using 50 hollow cones made of recycled cardboard. Each cone has a base diameter of 40 centimeters and height 1 meter. If the outer side of each of the cones is to be painted and the cost of painting is to be 12 square meters, what will be the cost of painting all these cones? Use pi equals to 3.14 and take square root of 1.04 equals to 1.02. Let us now begin the disillusion. We will first write down the given information. We are given that diameter of cone is 40 centimeters. Now this implies radius of cone is equal to 40 by 2 centimeters and this is equal to 20 centimeters. We are given the height of cone in meters and we are also given the cost of painting as to be 12 per meter square. So we have to convert radius into meters. So on converting 20 centimeters into meters we get 0.2 meters. Now look at the question again. Question says a bus stop is varicated from the remaining part of the road by using 50 hollow cones. Now each cone has base diameter of 40 centimeters and height 1 meter. If the outer side of each of the cones is to be painted and the cost of painting is to be 12 per meter square, what will be the cost of painting all these cones? Now outer side means we have to paint on the curve surface of the cone and all these cones are to be painted. So this means we will first find curve surface area of one cone and then we will find curve surface area of 50 cones by multiplying curve surface area of one cone by 50. Then it is given to us that cost of painting gets to be 12 per meter square. So we will find cost of painting all these cones by multiplying curve surface area of 50 cones by rupees 12. So let's first find curve surface area of one cone. The question we are given that height of each cone is equal to 1 meter. Now curve surface area of one cone is equal to pi rL. Let's calculate L. L is equal to square root of h square plus r square. On substituting values of h and r we get 1 square plus 0.04 meters and this is equal to square root of 1.04 meter. Now we are given in the question that we have to take square root of 1.04 as 1.02. So this is equal to 1.02 meters. Now substitute the value of pi rL pi is equal to 22 by 7 r is equal to 0.2 L is equal to 1.02 meters square. Now curve surface area of three cones is equal to 50 into 22 by 7 into 0.2 into 1.02 meters square. Since cost of painting 1 meter square is rupees 12 therefore cost of painting 50 into 22 by 7 into 0.2 into 1.02 meters square is rupees 12 into 50 into 22 by 7 into 0.2 into 1.02 and this is equal to rupees 384.34 approximately. Hence our required answer is rupees 384.34 approximately. So this completes the session by a thank you.