 Hello and welcome to the session. In this session we discussed the following question which says the diameter of the wheel of a car is 84 centimeters. How many revolutions will it make to travel 26.4 kilometers? First let's recall the formula for the circumference of a circle. This is equal to 2 pi r where r is the radius of the circle. This is the key idea that we use in this question. Let's move on to the solution now. We are given the diameter of the wheel is equal to 84 centimeters. So therefore the radius of the wheel is equal to 84 upon 2 centimeters which is equal to 42 centimeters. Now the circumference of the wheel is equal to 2 pi r that is equal to 2 into 22 upon 7 that is the value for pi into r that is the radius of the wheel which is 42 centimeters is the circumference of the wheel. Now 7 6 times is 42 so this is equal to 264 centimeters is the circumference of the wheel. Now the distance covered by the wheel in one revolution is equal to the circumference of the wheel which is 264 centimeters or you can say this is equal to 264 upon 100 meters or equal to 2.64 meters is the distance covered by the wheel in one revolution. Now we have 2.64 meters is covered by the car in one revolution. So therefore 26.4 kilometers which is equal to 264 double zero meters is covered by the car in one upon 2.64 into 264 double zero revolutions that is this is equal to 264 double zero into 100 upon 264 now 264 100 times is 264 double zero so this is equal to 100 into 100 equal to 1 0 0 0 0 revolutions. So thus we have the required number of revolutions is equal to 10,000. So 10,000 is our final answer. This completes the session. Hope you have understood the solution for this question.