You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

[EX Q]: Context: Marco and his dad went strawberry picking. Marco's strawberries weighed 30 pounds. If together their strawberries weighed 47 pounds. 

 Question: How much more did his strawberries weigh than his dad's?
[EX A]: 13

[EX Q]: Context: Rachel had to complete 5 pages of math homework and 2 pages of reading homework. 

 Question: How many more pages of math homework than reading homework did she have?
[EX A]: 3

[EX Q]: Context: Dave had 24 files and 13 apps on his phone. After deleting some apps and files he had 17 apps and 21 files left. 

 Question: How many files did he delete?
[EX A]:
3