Question

Find the value of k if k+1,2k+1 and 13 are 3 consecutive terms of an arithmetic sequence ?

Answer 1

First termt of tge consecutive terms,
a=k + 1
Next tern, a+d= 2k + 1
Last of the thre,
a+2d =13

(a) +(a+2d) =2 * (a+d)
=> k+1+13 = 2*(2k+1)
Solving the equation,
k = 4