 Hi and welcome to the session. Let us discuss the following question. Question says, a 20 meter deep fill with diameter 7 meters is dug and the earth from digging is evenly spread out to form a platform 22 meters by 14 meters. Find the height of the platform. First of all let us understand that volume of cylinder is equal to pi r square h where r is the radius and h is the height of the cylinder and volume of cuboid is equal to length multiplied by breadth multiplied by height. Here l represents length, b represents breadth and h represents height of the cuboid. Now we will use these formulas as our key idea to solve the given question. Let us now start with the solution. First of all let us understand the question. We know well is in the form of cylinder. Earth dugout from the well is spread out on a platform. So this implies volume of earth dugout is equal to volume of platform. First of all we will find out volume of the earth dugout. We know volume of the earth dugout is equal to volume of this cylindrical well. Now depth of the well is 20 meters. So we can write depth of the well is equal to height of the cylinder that is h. So h is equal to 20 meters. Now diameter of the well is equal to 7 meters. So radius of the well that is r is equal to 7 upon 2 meters. We know radius is equal to half of diameter. Now we can write volume of earth dugout is equal to volume of cylindrical well. We know volume of cylinder is equal to pi r square h. So volume of cylindrical well is equal to pi r square h. Now substituting corresponding values of h, r and pi in this expression we get 22 upon 7 multiplied by square of 7 upon 2 multiplied by 20 meter cube. Now this can be further simplified as 22 upon 7 multiplied by 7 upon 2 multiplied by 7 upon 2 multiplied by 20 meter cube. Now on simplifying we get volume of earth dugout is equal to 770 meter cube. Now we are given in the question that the earth is spread out to form a platform whose length is 22 meters and breadth is 14 meters. So we can write length of platform that is l is equal to 22 meters and breadth of platform that is b is equal to 14 meters. Now we have to find height of platform. So we will find the value of h since earth dugout from the well is spread out to form a platform. So volume of this cylindrical well or we can say volume of earth dugout is equal to volume of platform so we can write volume of platform is equal to volume of earth dugout. Now volume is in the shape of a cuboid so volume of platform is given by length multiplied by breadth multiplied by height and this volume is equal to volume of earth dugout and volume of earth dugout is equal to 770 meter cube. Now substituting corresponding values of l and b in this expression we get 22 multiplied by 14 multiplied by h is equal to 770. Now dividing both the sides of this expression by 22 multiplied by 14 we get 770 upon 22 multiplied by 14 is equal to h. Now simplifying this expression we get 5 upon 2 meters is equal to h. Now this is further equal to 2.5 meters so we get height of the platform is equal to 2.5 meters so this is our required answer. This complete sufficient hope you understood the solution. Take care and have a nice day.