Question

27. (2) ( frac{1}{2}+frac{1}{6}+frac{1}{12}+frac{1}{20}+frac{1}{30} )
( =frac{1}{1 cdot 2}+frac{1}{2 cdot 3}+frac{1}{3 cdot 4}+frac{1}{4 cdot 5}+frac{1}{5 cdot 6} )
( =left(1-frac{1}{2}right)+left(frac{1}{2}-frac{1}{3}right)+left(frac{1}{3}-frac{1}{4}right) )
( =1-frac{1}{6}=frac{5}{6} )
( +left(frac{1}{4}-frac{1}{5}right)+left(frac{1}{5}-frac{1}{6}right) )

# 27. Find the value of 1 1 1 + + + - 2 + - 6 - 12 1 - 20

Solution