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

Q: Problem: which number can we add to 425897 to get a number exactly divisible by 456 ?

A: 7
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Q: Problem: if a 1 mm thick paper is folded so that the area is halved at every fold , then what would be the thickness of the pile after 50 folds ?

A: 1 billion km', 'e ) none'
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Q: Problem: a hall 36 m long and 15 m broad is to be paved with stones , each measuring 2 dm by 5 dm . the number of stones required is :

A:
5400', 'd ) 18000', 'e ) 1.8'
****