In a row Ravi is 8th from left end Mohan is 10th from right end. Mohan is right to Ravi . If there are 4 persons between them . Then how many persons are there in the row.

22

Total number of persons in the row= Position of Ravi from left + Position of Mohan from right + persons in between Ravi and Mohan 

                                                  = 8 + 10 + 4 

                                                  = 22