The value of a piece of industrial machinery is decreasing by r% r\%\,r% each year.
The machinery's value will decrease by 45% in 4 years, work out the value of rrr.
Give your answer to 2 decimal places.
55 exam-style questions on Edexcel GCSE Maths Repeated Percentage Change. Each one has a worked solution and a mark scheme showing where the marks go.