#### Question

Find the sum to *n* terms of the A.P., whose *k*^{th }term is 5*k* + 1.

#### Solution

It is given that the *k*^{th} term of the A.P. is 5*k* + 1.

*k*^{th} term = *a*_{k} = *a *+ (*k* – 1)*d*

∴ *a *+ (*k* – 1)*d* = 5*k* + 1

*a* + *kd* – *d* = 5*k* + 1

Comparing the coefficient of *k*, we obtain *d* = 5

*a *– *d *= 1

⇒ *a* – 5 = 1

⇒ *a* = 6

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Solution Find the Sum to N Terms of the Arithmetic Progression, Whose Kth Term is 5k + 1. Concept: Arithmetic Progression (A.P.).

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