In a freshwater river catchment, a survey estimates that there are 5,6505,6505,650 native white-clawed crayfish and 118,200118,200118,200 invasive signal crayfish.
Calculate the percentage of all crayfish in this catchment that are native white-clawed crayfish.
Show your working and give your answer to one decimal place.
31 exam-style questions on Edexcel IGCSE Biology The organism in the environment. Each one has a worked solution and a mark scheme showing where the marks go.