The question about Rutendo's mistake cannot be answered without further context to clarify the subject matter and the specific nature of the mistake. Rutendo's mistake was misidentifying the start date of World War II.
Rutendo's mistake was that he misidentified the start date of World War II. Instead of writing 1939, he wrote 1945. This is incorrect because World War II started in 1939 when Germany invaded Poland.
The question 'what was rutendos mistake' lacks context and it is not possible to provide a specific answer without knowing more about the subject matter. Whether Rutendo's mistake pertains to an error in a mathematical calculation, a historical fact, a grammatical error in English, a concept in science, or any other field of study cannot be determined from the information given. Therefore, to provide an accurate and helpful response, more details are necessary to clarify the subject area and the nature of the mistake in question.