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.

Context: Dave had 24 apps and 9 files on his phone. After deleting some apps and files he had 5 files and 12 apps left. 

 Question: How many more apps than files does he have left on the phone?
7

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?
3

Context: Each pack of dvds costs 76 dollars. If there is a discount of 25 dollars on each pack 

 Question: How much do you have to pay to buy each pack?

51