python question

A bicycle shop sells bikes and helmets. Some people already own helmets, so on average the shop sells one helmet for every five bicycles. Helmets cost $50 and bikes cost $300. Your second function will take as an input variable (called an argument) the number of bikes that are expected to be sold over the next month. The function should return the expected total sales dollars taken in given the proportions above. The second function you will write should be called expectRev. Your function should take one (1) argument, an integer representing the expected number of bikes sold. The function should return one (1) integer: the expected revenue. Note that no helmets are expected to be sold until the 5th bike is sold Note: Do not do any explicit rounding. Testing: Create your own test cases. Think about what the edge cases are. We will only pass whole, non- negative numbers into your function