Math Problem Statement

What is a formula for the nth term of the given sequence? 60, 150, 375...

Solution

The question asks for the formula of the nth term in the sequence: 60,150,375,60, 150, 375, \dots.

To determine this, let’s observe the ratio between consecutive terms:

15060=2.5,375150=2.5\frac{150}{60} = 2.5, \quad \frac{375}{150} = 2.5

This indicates a geometric sequence with a common ratio r=2.5r = 2.5.

The general formula for the nth term of a geometric sequence is:

an=a1rn1a_n = a_1 \cdot r^{n-1}

Where:

  • a1=60a_1 = 60 (the first term),
  • r=52r = \frac{5}{2} (common ratio).

Thus, the formula for the nth term is:

an=60(52)n1a_n = 60 \cdot \left( \frac{5}{2} \right)^{n-1}

From the given choices, the correct answer is:

an=60(52)n1a_n = 60 \left( \frac{5}{2} \right)^{n-1}

Do you have any questions or want further details?

Related Questions:

  1. How do you find the common ratio in a geometric sequence?
  2. What is the difference between an arithmetic and a geometric sequence?
  3. Can the nth term formula be applied to find any term in the sequence?
  4. How would you determine the sum of the first n terms in this geometric sequence?
  5. What happens if the common ratio is less than 1 in a geometric sequence?

Tip:

Always check the common ratio in geometric sequences by dividing successive terms to verify if the pattern holds.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Geometric Sequences

Formulas

nth term formula for geometric sequence: a_n = a_1 * r^(n-1)

Theorems

Geometric Sequence Formula

Suitable Grade Level

Grades 9-12