Question

What are the next 2 terms in the following sequence?
-1, -3, -5, -7,…
A. -8, -10
B. -8, -9
C. 9, 11
D. -9, -11

Answer 1

going from -1 to -3, you add on -2 (ie you subtract 2)

going from -3 to -5, you add on -2 (ie you subtract 2)

etc etc

Answer 2

D

Answer 3

Technically, the next two terms can be *anything*. Instead, what is implicitly being asked is, what are the next two terms with the assumption that we prefer the simplest function that maps the whole numbers to the given sequence. (This is an application of Occam's razor.)

In that case, f(n) = -2*n - 1

So, f(0) = -1, f(1) = -3, f(2) = -5, f(3) = -7, f(4) = -9, and f(5) = ?

But, do note that any function that matches the given prefix, -1, -3, -5, and -7, is possibly correct. The only way to throw out a hypothesis (a function) that matches the data (evidence) so far is by acquiring more evidence, e.g., if the next number in the sequence was actually 9, then simple function f given can be rejected.