Photographic film is rolled on a CD.

The first lap length =60π mm, the second lap length =(60+0.3)π mm … the nth lap length =[60+0.3(n- 1)]π mm, the 600th lap length =(60+0.3×599)π mm,

Total length = 60 π+(60+0.3) π+(60+0.3× 2) π+… (60+0.3× 599) π. (5 points)

=[60×600+0.3×( 1+2+3+…+599)]π,

=899 10π (mm), (4 points)

≈ 282.3m. ( 1)