(1) should be 8 revolutions per minute? The diameter of the front wheel of the roller is 1.5m, and the circumference is 1.5 * 3. 14m, with 8 revolutions per minute, that is, the roller advances 8 * 1.5 * 3. 14m per minute.

(2) The circumference of the circular lawn is = 628 * 0.5 = 3 14m, so the diameter of this lawn is 314/3.14 =100m.

(3) The diameter of the circle is 18.84/3. 14=6 cm, so the area of this square paper is 6*6=36 cm.