PGEE 2018

Question

let 5,8,11,14,17,20.. be series then 320 will be which term of this series

A) 104

B) 106

C) 962

D) 87

Answer 1

as we can see the difference between consecutive term is 3 so this is an AP series

d=3 we know a=5 and Tn=320

Tn=a+(n-1)d substituting all know values we get

320=5+(n-1)3

315=(n-1)3

n-1=105

n=106

so 320 will be a 106th term of this series

Answer 2

b

 

2+3n is the nth term of this solution

 

for   2+3n=320

n  = 106

Answer 3

We can see that given series is in Arithmetic progression with first term 5 and common difference 3 so using formula Tn=a+(n-1)d where a is first term and d is common difference then 320=5+(n-1)3 solving this n-1=315/3 hence n-1=105 and n=106.

Answer 4

5,8,11,14,17,20,………

a=5

d=3

an = a + (n − 1) × d an=320 320=5+(n-1)3 n=106