Question

1. The first , second and last terms of an A.P. series are 5,9 and 101 respectively. Find the number of
terms in A.P. series and also find the sum of all terms.
(2.5)​

Answer 1

Step-by-step explanation:

first term = a= 5

Common difference = d= 4

Last term = l =101

a+(n-1)d = 101

4n+1 = 101

No. of terms = n= 25

Sum of all 25 terms = n/2(2a+(n-1)d)

= 25/2*106

= 1325

Answer 2

Step-by-step explanation:

here is your answer please