The task is to generate the correct answer for a given math problem.
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Question: Problem: mary can do a piece of work in 26 days . rosy is 30 % more efficient than mary . the number of days taken by rosy to do the same piece of work is ?

Answer: 20

Question: Problem: what ratio must a shopkeeper mix peas and soybean of rs . 16 and rs . 25 / kg , as to obtain a mixture of rs . 21.50 ?

Answer: 7 : 11

Question: Problem: a and b can do a work in 5 days and 10 days respectively . a starts the work and b joins him after 4 days . in how many days can they complete the remaining work ?

Answer:
2 / 3 days