Given the following reasoning and answer, what was the question? One pizza costs twice as much as the burger, which means 9 * 2 = $18. Three burgers would cost 9 * 3 = $27. So one pizza and three burgers would cost in total 18 + 27 = $45.
 The answer: 45

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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The question In a restaurant, a burger costs $9, and a pizza twice as much. How much would cost one pizza and three burgers?