The task is to generate the correct answer for a given math problem.
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Question: Problem: when positive integer n is divided by 5 , the remainder is 1 . when n is divided by 7 , the remainder is 3 . what is the smallest positive integer k such that k + n is a multiple of 40 .

Answer: 7


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

Answer: 7


Question: Problem: a person borrows rs . 7000 for 2 years at 4 % p . a . simple interest . he immediately lends it to another person at 6 p . a for 2 years . find his gain in the transaction per year .

Answer:
140 rs