Question

The first and last terms of an AP are 17and 350 respectively ,if the common difference is 9 ,how many terms are there and what is their sum​

Answer 1

Answer:

Step-by-step explanation:

T(n)= a+(n-1)*d

T(n)= last term which is 350

a= 17 ,d = 9

350=17+(n-1)*9

n= 38

Sum = (first term+last term)*n/2

(17+350)*38/2

=6973

Answer 2

Step-by-step explanation:

Given:

A=17 and D=9 and An=350

350=17+[n-1]9

333=[n-1]9

37=n-1

Therefore "n" is =38

Sn=n/2{a+An}

=38/2{17+350}

=19*367

=6973

Number of terms is 38 and their sum is 6973

Hope that it will help you