How many terms of the A.P. 25, 22, 19, .... are needed to give the sum 116 ? Also find the last term.

Let the number of terms required be n. For the given A.P., a = 25, d = 22 - 25 = -3, S n = 116 By formula, S n = Since, number of terms will be a natural number so n ≠ ∴ n = 8. By formula S n = ⇒ 116 = ⇒ 116 = 4[25 + l] ⇒ 29 = 25 + l ⇒ 29 - 25 = l ⇒ l = 4. Hence, number of terms = 8 and the last term = 4.

How many terms of the A.P. 24, 21, 18, … must be taken so that the sum is 78 ? Explain the double answer.

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Solve for x : 1 + 4 + 7 + 10 + … + x = 287.

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The first and the last terms of an A.P. are 17 and 350 respectively. If the common difference is 9, how many terms are there and what is their sum?

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Find the sum of first 22 terms of an A.P. in which d = 7 and a₂₂ is 149.

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Mathematics

How many terms of the A.P. 25, 22, 19, …. are needed to give the sum 116 ? Also find the last term.

AP GP

Related Questions

How many terms of the A.P. 24, 21, 18, … must be taken so that the sum is 78 ? Explain the double answer.

Solve for x : 1 + 4 + 7 + 10 + … + x = 287.

The first and the last terms of an A.P. are 17 and 350 respectively. If the common difference is 9, how many terms are there and what is their sum?

Find the sum of first 22 terms of an A.P. in which d = 7 and a₂₂ is 149.

Mathematics

How many terms of the A.P. 25, 22, 19, …. are needed to give the sum 116 ? Also find the last term.

AP GP

Related Questions

How many terms of the A.P. 24, 21, 18, … must be taken so that the sum is 78 ? Explain the double answer.

Solve for x : 1 + 4 + 7 + 10 + … + x = 287.

The first and the last terms of an A.P. are 17 and 350 respectively. If the common difference is 9, how many terms are there and what is their sum?

Find the sum of first 22 terms of an A.P. in which d = 7 and a22 is 149.

Find the sum of first 22 terms of an A.P. in which d = 7 and a₂₂ is 149.