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

Ex Input:
Problem: . 005 / ? = . 01

Ex Output:
. 5


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 total of $ 20,000 was invested in two certificates of deposit at simple annual interest rates of 6 percent and 12 percent , respectively . if the total interest on the two certificates was $ 1,440 at the end of one year , what fractional part of the $ 20.000 was invested at the higher rate ?

Ex Output:

1 / 5