I'm totally stuck on the following question and so I'd very very grateful if someone could please tell me how to work it out.(adsbygoogle = window.adsbygoogle || []).push({});

The first three terms of an arithmetic series are (12-P), 2P and (4P-5) respectively, where P is a constant.

(a) Find the value of P.

(b) Show that the sixth term of the series is 50.

(c) Find the sum of the first 15 terms of the series.

(d) Find how many terms of the series have a value of less than 400.

Thank you.

Cathy

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# Homework Help: Arithmetic Series help (AS Level)

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