|A) 3 am||B) 12 pm|
|C) 1 pm||D) 3 pm|
Work done by P and Q in the first two hours, working alternately
= First hour P + Second hour Q
work is completed in 2 hours
Then, the total time required to complete the work by P and Q working alternately=23=6hours
Thus, work will be completed at 3pm.