The task is to generate the correct answer for a given math problem.

Ex Input:
Problem: a man purchased earphone on friday . but he forgot how much it cost . the data he have are mean expenditure of all 7 days is 500 . expenditure on mon , tue , wed , thurs , sat , sun are 450600 , 400500 , 550300 . on friday he purchased 3 things one earphone , one pen and one notebook . pen cost 30 and notebook cost 50 . then what is cost of earphone ?

Ex Output:
620


Ex Input:
Problem: a salt manufacturing company produced a total of 2000 tonnes of salt in january of a particular year . starting from february its production increased by 100 tonnes every month over the previous months until the end of the year . find its ave 66 rage daily production for that year ?

Ex Output:
83


Ex Input:
Problem: stacy was 5 days late returning items to the library . stacy had checked out 40 books , 2 movies , and 3 magazines . books are fined $ 0.25 per day , movies are fined $ 3.00 per day , and magazines are fined $ 0.50 per day . what is the average fine per item per day stacy paid ?

Ex Output:

none of the abov