Edexcel C1 2011 June — Question 9

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Year2011
SessionJune
TopicArithmetic Sequences and Series

  1. (a) Calculate the sum of all the even numbers from 2 to 100 inclusive,
$$2 + 4 + 6 + \ldots \ldots + 100$$ (b) In the arithmetic series $$k + 2 k + 3 k + \ldots \ldots + 100$$ \(k\) is a positive integer and \(k\) is a factor of 100 .
  1. Find, in terms of \(k\), an expression for the number of terms in this series.
  2. Show that the sum of this series is $$50 + \frac { 5000 } { k }$$ (c) Find, in terms of \(k\), the 50th term of the arithmetic sequence $$( 2 k + 1 ) , ( 4 k + 4 ) , ( 6 k + 7 ) , \ldots \ldots ,$$ giving your answer in its simplest form.