If a sequence has first term 5 and common ratio 3, what is a4?

Prepare for the CCC Common Core Test. Utilize flashcards and multiple-choice questions with detailed hints and explanations to ensure you're ready for exam day!

Multiple Choice

If a sequence has first term 5 and common ratio 3, what is a4?

Explanation:
In a geometric sequence, each term is obtained by multiplying the previous term by the common ratio. Starting with a1 = 5 and r = 3, we get a2 = 5×3 = 15, a3 = 15×3 = 45, and a4 = 45×3 = 135. Using the formula a_n = a1 × r^(n−1), a4 = 5 × 3^3 = 5 × 27 = 135. So the value is 135. (For reference, a5 would be 135×3 = 405, which is why that number appears in the options, but it corresponds to the fifth term, not the fourth.)

In a geometric sequence, each term is obtained by multiplying the previous term by the common ratio. Starting with a1 = 5 and r = 3, we get a2 = 5×3 = 15, a3 = 15×3 = 45, and a4 = 45×3 = 135. Using the formula a_n = a1 × r^(n−1), a4 = 5 × 3^3 = 5 × 27 = 135. So the value is 135. (For reference, a5 would be 135×3 = 405, which is why that number appears in the options, but it corresponds to the fifth term, not the fourth.)

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy