Question 13
Evaluate:
(a) $\frac1{5\times8}+\frac1{8\times11}+\frac1{11\times14}+\cdots+\frac1{98\times101}$.
(b) $\frac12-\frac5{12}+\frac7{24}-\frac9{40}+\frac{11}{60}-\frac{13}{84}+\frac{15}{112}-\frac{17}{144}$.
Answer entry: give (a) then (b) as simplified fractions numerator/denominator, separated by one semicolon, with no spaces; for example 1/2;3/4.
(a) $\frac1{5\times8}+\frac1{8\times11}+\frac1{11\times14}+\cdots+\frac1{98\times101}$.
(b) $\frac12-\frac5{12}+\frac7{24}-\frac9{40}+\frac{11}{60}-\frac{13}{84}+\frac{15}{112}-\frac{17}{144}$.
Answer entry: give (a) then (b) as simplified fractions numerator/denominator, separated by one semicolon, with no spaces; for example 1/2;3/4.