Question

In an A. P. The addition of 7term is 63 the first term is 3 then find out 7term

Answer 1

Answer:

The seventh term = 15.

Explanation:

S7 = 63

a = 3

a7 = a + 6d

$\\ sn = \frac{n}{2} (2a + 6d) \\ s7 = \frac{7}{2} (2 \times 3 + 6d)$

$63 = \frac{7}{2} (6 + 6d) \\ 63 = 7(3 + 3d) \\ 9 = 3 + 3d \\ 3d = 9 - 3 = 6 \\ d = 2$

We know that,

$a7 = a + 6d \\ a7 = 3 + 6 \times 2 \\ a7 = 3 + 12 = 15$

Hence the seventh term = 15.

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{ I hope the question was as follows :

In an A. P. The sum of 7 terms is 63, the first term is 3. Then find out 7th term.}

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Hope it helps.....!

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