For a batch of parts, it takes 8 hours for Party A to produce them alone. Now, after Party A has done it for 2 hours, Party B has joined in the work, and it takes 4 hours for them to complete the task. It takes Party B to produce these parts alone___ Hours

For a batch of parts, it takes 8 hours for Party A to produce them alone. Now, after Party A has done it for 2 hours, Party B has joined in the work, and it takes 4 hours for them to complete the task. It takes Party B to produce these parts alone___ Hours

It takes 16 hours for Party B to finish this batch of parts alone