Question

A LIST OF 300 NUMBERS START AT 1.AFTER THAT EVERY NUMBER IS TRIPLED THE NUMBER WHICH IT HAD PRECEDES IT.THE 200TH NUMBER ON THE LIST IS

A:600
B:900
C:3 to the 199 power
D:3 to the 200 power

Answer 1

Since each term is a multiple of the previous term, this is a geometric sequence, because there is a common ratio. (The constant found when dividing any term by the previous term.) Any geometric sequence can be expressed as:

a(n)=ar^(n-1), where a=initial term, r=common ratio, n=term number:

We are told that a=1 and r=3 so

a(n)=3^(n-1), so the 200th term is:

a(200)=3^199

So your answer is C.