Question

[tran duc chuan]

1/2+ 1/6+ 1/12 +1/20+...+1/9702 +1/9900

Answer 1

[Khong Biet]

\(\frac{1}{2}+\frac{1}{6}+............+\frac{1}{9900}\)

\(=\frac{1}{1.2}+\frac{1}{2.3}+............+\frac{1}{99.100}\)

\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...........+\frac{1}{99}-\frac{1}{100}\)

\(=1-\frac{1}{100}\)

\(=\frac{99}{100}\)

Answer 2

[soong Joong ki]

99

100