Juliet is selling photographs as part of a project for her entrepreneurship class. She sells the first 20 photographs for $10 each. Because the first 20 photographs sold so quickly, she raised the price of the photographs to $15 each for the rest of the project. After her expenses, Juliet earns a profit of 80% of the revenues from her sales. What is the least number of photographs she must sell for the rest of the project to earn a profit of at least $400?
A) 18B) 20C) 24D) 32