Question

Which term of the AP 3,10,17....wil be 84 move than 13th term?

Answer 1

EXPLANATION.

Which term of the AP,

3, 10, 17, . . . . . will be 84 more than 13th term.

As we know that,

Formula of :

General term of an A.P.

⇒ Tₙ = a + (n - 1)d.

Using this formula in the equation, we get.

First term = a = 3.

Common difference = d = b - a = c - b = 10 - 3 = 7.

Common difference = d = 7.

⇒ Tₙ = 84 + 13th term.

⇒ Tₙ = 84 + T₁₃.

⇒ Tₙ = 84 + a + (13 - 1)d.

⇒ Tₙ = 84 + a + 12d.

Put the values in the equation, we get.

⇒ Tₙ = 84 + 3 + 12(7).

⇒ Tₙ = 84 + 3 + 84.

⇒ Tₙ = 171.

⇒ Tₙ = a + (n - 1)d.

⇒ 171 = 3 + (n - 1)(7).

⇒ 171 = 3 + 7n - 7.

⇒ 171 = 7n - 4.

⇒ 175 = 7n.

⇒ n = 25.

25th term of an A.P. is 84 more than 13th term.

                                                                                                                   

MORE INFORMATION.

Supposition of terms in an A.P.

(1) Three terms as : a - d, a, a + d.

(2) Four term as : a - 3d, a - d, a + d, a + 3d.

(3) Five terms as : a - 2d, a - d, a, a + d, a + 2d.

Answer 2

✱ Question

➊ Which term of the AP 3,10,17....wil be 84 move than 13th term?

✿ Solution

☻ The required answer is 25

✱ Explanation

⫸ Refer the attachment given below

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