You are given a math word problem and you are supposed to apply a single mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report final the numerical answer.

[Q]: There are 4 marbles . 7 marbles more are added . How many are there total ?
[A]: 11


[Q]: Joan purchased a basketball game for $ 5.2 , and a racing game for $ 4.23 . How much did Joan spend on video games ?
[A]: 9.43


[Q]: A lawyer bills her clients 200 dollars per hour of service . If a client 's case requires 39 hours to complete , use proportion to calculate how much the client will owe the lawyer in dollars .
[A]:
7800