Question

Consider the first four terms of the sequence below. -3, -12, -48, -192, . . . What is the 8th term of this sequence? A. -49,152 B. -768 C. -12,288 D. -196,608

Answer 1

Answer:

A

Step-by-step explanation:

there is a common ratio between consecutive terms , that is

- 12 ÷ - 3 = - 48 ÷ - 12 = - 192 ÷ - 48 = 4

this indicates the sequence is geometric with nth term

$a_{n}$ = a₁ $r^{n-1}$

where a₁ is the first term and r the common ratio

here a₁ = - 3 and r = 4 , then

a₈ = - 3 × $4^{7}$ = - 3 × 16,384 = - 49,152