1/(1*3) + 1/(3*6) + 1/(6*9) + 1/(9*12) + …+1/(96*99)
=1/3 + 1/3*(1/3-1/6+1/6-1/9 + .-1/96+1/96-1/99 )
=1/3 + 1/3*(1/3-1/99)
=1/3*(1+1/3-1/99)
=395/27
1/(1*3) + 1/(3*6) + 1/(6*9) + 1/(9*12) + …+1/(96*99)
=1/3 + 1/3*(1/3-1/6+1/6-1/9 + .-1/96+1/96-1/99 )
=1/3 + 1/3*(1/3-1/99)
=1/3*(1+1/3-1/99)
=395/27