Compute the Sum of geometric series

50 Views Asked by At

Basically, I just came out of my exam and this was a question that I wasn't sure of how to solve, I'd appreciate it if someone answered this

$$\sum_{k=1}^{99}\frac{1}{k(k+1)}$$

1

There are 1 best solutions below

2
On

Hint: $$\frac1{k(k+1)}=\frac1k-\frac1{k+1}$$ Now write out the terms of the summation in this form and see which fractions cancel out. This is probably the most well-known example of what is known as a telescoping sum.