Question 389902
   <pre><font size = 3 color = "indigo"><b>
Hi,        
Find the sum of all intergers between 1 and 200 that are divisible by 6
Describes a arithmetic sequence {6,12,18,24...198}}} first term 6, d = 6
{{{a[n]=a[1]+(n-1)*d}}} 
{{{a[33]= 6+ 6(32)=198}}} 
{{{S[n]=(n/2)(2*a[1]+ (n-1)d)}}}
{{{S[33]=(33/2)(12+ 192)= 33/2*204 = highlight(3366)}}}