problem 639

Find S10 for 2 + 5 + 8 +…

 

Solution:-

 

We know S =  \frac{n}{2}[2a_{1}+(n-1)d] , Where a1 = first term , n = finding term , d = second term – first term.

S10 =  \frac{10}{2}[2*2_{1}+(10-1)3]

S10 = 155

So the value of S10 155.

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *