Question

Is 402 a term of the sequence:

8, 13, 18, 23, ................. ?  

Answer 1

The given sequence is 8, 13, 18, 23, .................

Now,

13 – 8 = 5

18 – 13 = 5

23 – 18 = 5, etc.

Hence, the given sequence is an A.P. with first term a = 8 and common difference d = 5.

The general term of an A.P. is given by

t_n = a + (n – 1)d

`=>` 402 = 8 + (n – 1)(5) 

`=>` 394 = 5n – 5

`=>` 399 = 5n

`=> n = 399/5`

The number of terms cannot be a fraction.

So clearly, 402 is not the term of the given sequence.