\(A=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+....+\frac{2}{37.39}\)

   \(=\frac{1}{3}-\frac{1}{39}\)

  \(=\frac{12}{39}\)

\(B=\frac{3}{4.7}+\frac{3}{7.10}+\frac{3}{10.13}+....+\frac{3}{73.76}\)'

     \(=\frac{1}{4}-\frac{1}{76}\)

     \(=\frac{9}{38}\)