OCR Pure 1 2018 March — Question 5

Exam BoardOCR
ModulePure 1 (Pure Mathematics 1)
Year2018
SessionMarch
TopicArithmetic Sequences and Series

5 An ice cream seller expects that the number of sales will increase by the same amount every week from May onwards. 150 ice creams are sold in Week 1 and 166 ice creams are sold in Week 2. The ice cream seller makes a profit of \(\pounds 1.25\) for each ice cream sold.
  1. Find the expected profit in Week 10.
  2. In which week will the total expected profits first exceed \(\pounds 5000\) ?
  3. Give two reasons why this model may not be appropriate.