Let radius of the roller is r

Now, 1 rotation of the roller = circumference of the roller

Given, road roller makes 200 rotations in covering 2200 m

=> 2πr * 200 = 2200

=> 2πr = 2200/200

=> 2πr = 11

=> r = 11/2π

=> r = 11/(2 * 22/7)

=> r = (11*7)/(2 * 22)

=> r =  7/(2 * 2)

=> r = 7/4

=> r = 1.75

So, the radius of the roller is 1.75 m