2又2*5分之1+4又5*8分之1+6又8*11分之1+...+100又149*152分之1+102又152*155分之1=
(2+4+6+...+100+102)+(1/2*5+1/5*8+1/8*11+...+1/149*152+1/152*155)
=(2+102)*51/2+1/3(1/2-1/5+1/5-1/8+1/8-1/11+.+1/149-1/152+1/152-1/155)
=2652+51/310=2652又51/310