NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 5: Arithematic Progressions - Exercise 5.3
Question 10

Question. 10

Is 55 a term of AP \(7,10,13,\ldots\)? If yes, which term?

Answer:

Yes, the 17th term.

Detailed Answer with Explanation:

Step 1: Recall the formula for the \(n\)th term of an AP:

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

where \(a\) = first term, \(d\) = common difference, and \(n\) = term number.

Step 2: Identify values from the given AP \(7, 10, 13, \ldots\):

  • First term \(a = 7\)
  • Common difference \(d = 10 - 7 = 3\)
  • We need to check if 55 is a term.

Step 3: Put values in the formula:

\(55 = 7 + (n-1) \times 3\)

Step 4: Simplify the equation:

\(55 - 7 = (n-1) \times 3\)

\(48 = (n-1) \times 3\)

Step 5: Solve for \(n-1\):

\(n-1 = 48 \div 3 = 16\)

Step 6: Find \(n\):

\(n = 16 + 1 = 17\)

Final Answer: 55 is the 17th term of the AP.

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 5: Arithematic Progressions – Exercise 5.3 | Detailed Answers