Question

Answer 1

\(E=\dfrac{5}{11.16}+\dfrac{5}{16.21}+...+\dfrac{5}{61.66}\\ =\dfrac{1}{11}-\dfrac{1}{16}+\dfrac{1}{16}-\dfrac{1}{21}+...+\dfrac{1}{61}-\dfrac{1}{66}\\ =\dfrac{1}{11}-\dfrac{1}{66}\\ =\dfrac{5}{66}\)

Answer 2

\(=\dfrac{1}{11}-\dfrac{1}{16}+\dfrac{1}{16}-\dfrac{1}{21}+...+\dfrac{1}{61}-\dfrac{1}{66}\)

\(=\dfrac{1}{11}-\dfrac{1}{66}=\dfrac{5}{66}\)

Answer 3

\(E=\dfrac{1}{11}-\dfrac{1}{16}+\dfrac{1}{16}-\dfrac{1}{21}+...+\dfrac{1}{61}-\dfrac{1}{66}=\dfrac{1}{11}-\dfrac{1}{66}=\dfrac{5}{66}\)

Answer 4

\(\dfrac{5}{66}\)