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

[EX Q]: Olivia and her mom were picking carrots from their garden . Olivia picked 20 and her mother picked 14 . If only 19 of the carrots were good , how many bad carrots did they have ?
[EX A]: 15

[EX Q]: Each chocolate bar in a box cost $ 6 . If a box had 13 bars total and Zoe sold all but 6 bars , how much money would she have made ?
[EX A]: 42

[EX Q]: A new building needed 14 windows . The builder had already installed 5 of them . If it takes 4 hours to install each window , how long will it take him to install the rest ?
[EX A]:
36