B=\(\frac{1}{4}+\left(\frac{1}{5}+\frac{1}{6}+..........+\frac{1}{9}\right)+\left(\frac{1}{10}+\frac{1}{11}+.........+\frac{1}{19}\right)\)
\(B>\frac{1}{4}+\left(\frac{1}{9}+\frac{1}{9}+\frac{1}{9}+\frac{1}{9}+\frac{1}{9}\right)+\left(\frac{1}{19}+\frac{1}{19}+.....+\frac{1}{19}\right)\)
=\(\frac{1}{4}+\frac{5}{9}+\frac{9}{19}\)
\(\Rightarrow B>\frac{1}{4}+\frac{1}{2}+\frac{1}{2}=1\)