+0  
 
+1
407
1
avatar+598 

The $n^{\text{th}}$ term of a certain geometric series is given by $a\cdot r^{n-1}$, where $a$ and $r$ are positive integers and $r$ is greater than 1. Bill picks out $k$ different numbers in this sequence, all of which have the same number of digits. What is the largest possible value of $k$?

michaelcai  Oct 5, 2017
 #1
avatar+598 
0

k=4

 

a=5, 50, ....

 

r=2, slowest going up

michaelcai  Oct 6, 2017

13 Online Users

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.