NCERT Solutions
Class 10 - Mathematics - Chapter 5: ARITHMETIC PROGRESSIONS - Exercise 5.2
Question 6

Question. 6

Check whether -150 is a term of the AP: 11, 8, 5, 2, ...

Answer:

No

Detailed Answer with Explanation:

Step 1: Identify the first term and common difference.

The AP is: 11, 8, 5, 2, ...

First term: \(a = 11\)

Common difference: \(d = 8 - 11 = -3\)

Step 2: Use the general term formula of an AP.

The \(n\)-th term of an AP is given by:

\[a_n = a + (n - 1)d\]

We check whether for some positive integer \(n\), the term equals \(-150\):

\[a_n = -150\]

Substitute values of \(a\) and \(d\):

\[11 + (n - 1)(-3) = -150\]

Step 3: Solve for \(n\).

Expand:

\[11 - 3(n - 1) = -150\]

Distribute the -3:

\[11 - 3n + 3 = -150\]

Simplify left side:

\[14 - 3n = -150\]

Move 14 to the right:

\[-3n = -150 - 14 = -164\]

Divide both sides by -3:

\[n = \frac{164}{3}\]

Step 4: Interpret the result.

\(n = \frac{164}{3}\) is not a whole number.

Since the term number must be a positive integer, no such \(n\) exists.

Conclusion: \(-150\) is not a term of the given AP.

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