 Welcome to the session. I am Neha and I am going to help you with the following question. The question says a road roller takes 750 complete revolutions to move once over to level a road. Find the area of the road if the diameter of a road roller is 84 centimeters and length is 1 meter. Before proceeding for the solution let's recall the lateral surface area of a cylinder which is equal to 2 pi r h where r is the radius of the base of the cylinder and h is its height. This is the key idea for this question. Now let's see its solution. Road roller is in the form of a cylinder and thus the lateral surface area of the road roller is equal to the lateral surface area of the cylinder that is 2 pi r h. So we can write lateral surface area of the road roller is equal to 2 pi r h. Now when the road roller is rolled one time over the road then the area of the road which it levels will be equal to the lateral surface area of the road roller. Now we are given in the question that the diameter is equal to 84 centimeters. So here is equal to 84 centimeters. So this implies radius r will be equal to 84 upon 2 centimeters that is equal to 42 centimeters. And now in question we are given that the length of the road roller is 1 meter. Now the length is this one so this will act as the height of the cylinder or we can say the height of the road roller. So height is equal to 1 meter. Let's convert it into centimeters and we know that 1 meter is equal to 100 centimeters. So the height is 100 centimeters. Also we call height as h. Now let us find out the area in one revolution and that will be equal to the lateral surface area that is 2 pi r h. Now let us substitute the values of r and h and we will get 2 into pi is 22 by 7 into r that is 42 into h that is 100. And its unit will be centimeter into centimeter that is centimeter square. Here 7 and 42 will get cancelled by the common factors 7 and we will get 2 into 22 into 6 into 100 centimeter square that is 26400 centimeter square. Now in question we are given that the road roller takes 750 revolutions to cover the road. So to find the area of the road we need to find the area covered by the road roller at 750 revolutions. So area covered in 750 revolutions is equal to 750 into 26400 centimeter square which is equal to 198000 centimeter square. Now let us convert it into meters so this will be 19800000 upon 10000 meter square. So this will give us 19080 meter square. Therefore area of the road is equal to 19080 meter square. Thus 19080 meter square is our required answer for this question. With this we finish this session hope you must have understood the question. Goodbye take care and have a nice day.