NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 5: Arithematic Progressions - Exercise 5.2
Question 5

Question. 5

Is \(0\) a term of the AP \(31, 28, 25, \ldots\)? Justify your answer.

Answer:

No.

Detailed Answer with Explanation:

Step 1: In an Arithmetic Progression (AP), the first term is written as \(a\) and the common difference as \(d\).

Here, the first term \(a = 31\).

The common difference \(d = 28 - 31 = -3\).

Step 2: The formula for the \(n\)-th term of an AP is:

\(a_n = a + (n - 1) \times d\).

Step 3: We want to check if \(0\) is a term in this AP. So, put \(a_n = 0\).

\(0 = 31 + (n - 1)(-3)\)

Step 4: Simplify the equation:

\(0 = 31 - 3(n - 1)\)

\(0 = 31 - 3n + 3\)

\(0 = 34 - 3n\)

Step 5: Solve for \(n\):

\(3n = 34\)

\(n = \dfrac{34}{3}\)

Step 6: Since \(n\) must be a whole number (like 1, 2, 3, …) for the term to exist, and \(\tfrac{34}{3}\) is not a whole number, it means there is no such term.

Therefore, 0 is not a term of the given AP.

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 5: Arithematic Progressions – Exercise 5.2 | Detailed Answers