Math Problem Statement

Determine the arithmetic progression (A.P.) whose third term is 16 and whose 7th term exceeds the 5th term by 12.

Solution

The problem states:

"Determine the arithmetic progression (A.P.) whose third term is 16 and whose 7th term exceeds the 5th term by 12."

Let us solve this step-by-step:

General formula for an arithmetic progression:

The nn-th term of an A.P. is given by: an=a+(n1)da_n = a + (n-1)d where:

  • aa is the first term,
  • dd is the common difference,
  • nn is the term number.

Step 1: Use the information about the 3rd term.

For the 3rd term (a3a_3) of the A.P., we know: a3=a+2da_3 = a + 2d It is given that a3=16a_3 = 16. So: a + 2d = 16 \tag{1}


Step 2: Use the relationship between the 7th and 5th terms.

For the 7th term (a7a_7) and 5th term (a5a_5), we have: a7=a+6d,a5=a+4da_7 = a + 6d, \quad a_5 = a + 4d It is given that the 7th term exceeds the 5th term by 12: a7a5=12a_7 - a_5 = 12 Substitute the formulas for a7a_7 and a5a_5: (a+6d)(a+4d)=12(a + 6d) - (a + 4d) = 12 Simplify: 2d = 12 \implies d = 6 \tag{2}


Step 3: Solve for aa.

Substitute d=6d = 6 into Equation (1): a+2(6)=16a + 2(6) = 16 Simplify: a + 12 = 16 \implies a = 4 \tag{3}


Step 4: Write the A.P.

The first term is a=4a = 4 and the common difference is d=6d = 6. The A.P. is: 4,10,16,22,28,4, 10, 16, 22, 28, \dots


Final Answer:

The arithmetic progression is: 4,10,16,22,28,4, 10, 16, 22, 28, \dots


Would you like a detailed explanation of any specific step? Let me know!


Related Questions:

  1. What is the formula for the nn-th term of an arithmetic progression?
  2. How do you calculate the sum of the first nn terms of an A.P.?
  3. Can you derive the common difference dd from two known terms of the A.P.?
  4. How can you verify the consistency of the A.P. using the given conditions?
  5. What is the 15th term of this A.P.?

Tip:

When solving arithmetic progression problems, always translate the conditions into equations using the general formula for the nn-th term. This simplifies the process of finding aa and dd.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Progressions
Algebra

Formulas

nth term of an arithmetic progression: an = a + (n-1)d

Theorems

Properties of arithmetic progressions

Suitable Grade Level

Grades 9-10