Help with Math SAT Question from October 2014 SAT

Test Preparation
1

<p>5,15,45....</p>

<p>In the sequence above, 5 is the first term, and each term after the first term is found by multiplying the preceding term by 3. Which of the following is equal to one of the terms of the sequence for some positive integer k?</p>

<p>(A) 3^k
(B) 20(3^k)
(C) 45(3^k)
(D)3^2k
(E)15^2k</p>

2

<p>C is correct. For example k = 1 gives you the fourth term of the sequence. All the other choices can be eliminated.</p>

3

<p>Oh okay, thanks!</p>