Question

In an A.P the third term is four times the first term and sixth term is 17 and then n = ___

Answer 1

Answer:

An=3 n+1

Step-by-step explanation:

a+2 d=4*a

2 d=3 a

a+5 d=17

substituting both the equation that is,3 a-2 d=0 and a+5 d=17

we get d=3 and a=2

An=a+(n-1)d

=2+(n-1)3

=2+3 n-3

=3n-1