A can paint a house in 42 days and B can do it in 21 days. Along with C, they can finish the job in 7 days only. C alone can do the painting job in how many days?
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A can paint a house in 42 days and B can do it in 21 days. Along with C, they can finish the job in 7 days only. C alone can do the painting job in how many days?