instruction:
The task is to generate the correct answer for a given math problem.
question:
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 ?
answer:
620


question:
Problem: what is the units digit of 17 ^ 83 × 13 ^ 82 × 11 ^ 67 ?
answer:
4


question:
Problem: in how many years rs 100 will produce the same interest at 5 % as rs . 600 produce in 4 years at 10 %
answer:

4