 Hello and welcome to the session. Let us discuss the following question. It says, find the volume of a sphere whose surface area is 154 centimeters square. Let us first understand the formula for volume of sphere. Volume of sphere is equal to 4 by 3 pi r cube where r is the radius of the sphere and value of pi is 22 upon 7. To solve this question we also need to know the formula for surface area of sphere. It is 4 pi r square. So this knowledge will work as key idea. Let us now move on to the solution. We are given that the surface area of sphere is 154 centimeters square. Now to find the volume of the sphere we need to know the radius of the sphere and the surface area of the sphere is 4 pi r square. So this implies 4 pi r square is equal to 154 centimeters square. So this implies r square is equal to 154 upon 4 pi centimeter. Now substitute the value of pi. So this implies r square is equal to 154 upon 4 into 22 upon 22 upon 7. The value of pi is 22 upon 7 which is equal to 154 into 7 upon 22 into 4 is 88 which is equal to 12.25. This implies radius r is under the root of 12.25 which is equal to 3.5 centimeter. So the radius of the sphere is 5 centimeter. Now we need to find the volume of the sphere. Volume of sphere 4 by 3 pi r cube where r is 3.5 centimeter. So the volume is 4 by 3 into pi which is 22 upon 7 into r cube that is 3.5 cube. And the unit of volume is centimeter cube because unit of radius is centimeter so the unit of volume is centimeter cube. Simplifying this is 4 by 3 into 22 upon 7 into 3.5 into 3.5 into 3.5 centimeter cube which is again equal to 4 by 3 into 22 upon 7 into 35 upon 10 into 35 upon 10 into 35 upon 10 centimeter cube. And on simplifying this we get this to be equal to 179.67 centimeter cube which can also be written as the mixed fraction 179 2 by 3 centimeter cube. Hence the volume of the sphere is 179 2 by 3 centimeter cube. So this completes the question. Do remember the formula for surface area of the sphere and the volume of the sphere. So this completes the question. Bye for now. Take care. Have a good day.