Question

Is 144 a term of the AP 3, 7 ,11..........? Justify your answer.

Answer 1

3,7,1,.... is given Ap

First term = a = 3
common difference = d = a2 - a1 = 7-3 =4
let nth term = 144
a+(n-1)d = 144
3+(n-1)4 = 144
(n-1)4 =144-3
(n-1)4 =141
n-1 = 141/4
n= 141/4 +1
n= (141+4)/4
n= 145/4
Therefore
n should not be fraction
144 is not the term in an given AP