Question

If n is taken as 'n'th number, what is the expression for the given sequence
2, 5, 8, 11 ....... ?

• A. 3n - 1
• B. 3n
• C. 3n + 1
• D. 3n + 2

Answer 1

The correct option is A 3n - 1

In the given sequence of numbers,

1st number = $3\times 0$ + 2
2nd number = $3\times 1$ + 2 = 5
3rd number = $3\times 2$ + 2 = 8
4th number = $3\times 3$ + 2 = 11
. .
. .
. .
. .
. .
nth number = $3\times (n-1)$ + 2
= 3n - 3 + 2
= 3n - 1

$\therefore$ The expression for the sequence is 3n - 1.