3. 5 • 3^n (1 point)

a.15, 30, 45, 60
b.5, 15, 45, 135
c.0, 15, 45, 135
d.15, 45, 135, 405

is it a. or b.!!!!!?????
i think its b, my parents say b

5 answers

The given expression is a geometric progression, which means that successive terms are obtained by a constant multiplier.

If you look at the quotient between successive terms, (a) does not even give a constant ratio, so (a) is out.

For (c), there is a problem with the first two terms, 15/0 is not a number, so that's out too.

Between (b) and (d), both make geometric progressions according to the given expression, but n starts at 0 for (b) and starts at 1 for (d).

I would go with (b), as most GP start at n=0.
it was d!!!!!
whoa!!!!!
there's no problem with 15/0, since 3^0 = 1. But that also means that (c) is out because 5*3^n cannot ever be zero.

Can't see why you were so surprised at (d), since these sequences usually start with n=1 unless they say otherwise. (b) starts with n=0.
It is d
thx all, I had absolutely no idea what this question was asking so thx. The answer is D