A charity is delivering chicken and rice dinners to a shelter for the hungry. They have a hundred plates to deliver. The rice cost ten cents a plate and the chicken cost forty cents a plate. How many dollars did the charity spend on the food for the dinners? Let's think first. Chain of thought:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Each chicken and rice plate cost 10 + 40 = 50 cents. The charity spent 50 * 100 = 5000 cents for the dinners. There are 100 cents in a dollar, so the charity spent 5000 / 100 = $50 for the dinners.
Therefore, the answer is 50.