Question

8. Which of the following is the 43rd term of the arithmetic sequence 3,0-3, ...?

A-117
B 120
C. -123
D. -126​

Answer 1

C. -123.

Explanation:

nth term = a1 + d(n - 1)

43rd term = 3 + -3(43-1)

= 3 - 126

= -123.

Answer 2

C

Explanation:

The n th term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 3 and d = a₂ - a₁ = 0 - 3 = - 3 , thus

a₄₃ = 3 + (42 × - 3) = 3 - 126 = - 123 → C