NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 5: Arithematic Progressions - Exercise 5.3
Question 12

Question. 12

Split 207 into three parts in AP such that the product of the two smaller parts is 4623.

Answer:

67, 69, 71

Detailed Answer with Explanation:

Step 1: Let the three parts in Arithmetic Progression (AP) be \((a - d), a, (a + d)\).

This means the middle term is \(a\), the first term is smaller by \(d\), and the last term is larger by \(d\).

Step 2: According to the question, the sum of the three parts is 207.

So, \((a - d) + a + (a + d) = 207\).

Simplify: \(3a = 207\).

Therefore, \(a = \dfrac{207}{3} = 69\).

Step 3: Now the three numbers are \((69 - d), 69, (69 + d)\).

Step 4: The product of the two smaller parts is given as 4623.

The two smaller parts are \((69 - d)\) and 69.

So, \(69 \times (69 - d) = 4623\).

Step 5: Expand the equation:

\(69 \times 69 - 69d = 4623\).

\(4761 - 69d = 4623\).

Step 6: Bring terms together:

\(4761 - 4623 = 69d\).

\(138 = 69d\).

Step 7: Solve for \(d\):

\(d = \dfrac{138}{69} = 2\).

Step 8: Substitute \(d = 2\):

First part = \(69 - 2 = 67\).

Second part = \(69\).

Third part = \(69 + 2 = 71\).

Final Answer: The three parts are 67, 69, 71.

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