TASK DEFINITION: The task is to generate the correct answer for a given math problem.
PROBLEM: Problem: audrey 4 hours to complete a certain job . ferris can do the same job in 3 hours . audrey and ferris decided to collaborate on the job , working at their respective rates . while audrey worked continuously , ferris took 5 breaks of equal length . if the two completed the job together in 2 hours , how many minutes long was each of ferris ' breaks ?

SOLUTION: 6

PROBLEM: 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 ?

SOLUTION: 7 : 11

PROBLEM: Problem: what is next no . 11 23 47 83 131 191 263 347 443 551 ? ? ?

SOLUTION:
67