The Zulu Social Aid & Pleasure Club first rolled with floats for Mardi Gras 1915. Their floats in 1915 were modest and only cost $500 per float. As the krewe grew in size, they spent an additional $75 per float each year until 1960. a. Write the first four terms of this sequence. b. Annotate the sequence and evaluate the common difference or common ratio. c. Is this sequence arithmetic or geometric?