Are You already working in company, where hope to be Sr engineer? If yes, it is possible, You will find somebody, who will work second half of work planned for

Are You already working in company, where hope to be Sr engineer? If yes, it is possible, You will find somebody, who will work second half of work planned for you, and You will manage him and be responsible for these two half's. Yes, real business questions, when somebody ask to do half of work, are, who will do other half, and who will manage this additional person. If You could give strongly supported answer for these questions, You will hit.