In a row of students, Sumit is 15th from the right end and Neeraj is 20th from the left end. What is the minimum number of students in the row?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 20
The row is smallest when the two counts overlap, that is, when Sumit stands to the left of Neeraj. The row can never be shorter than the larger of the two positions.
Neeraj is 20th from the left, so the row has at least 20 students
Try a row of 20: Neeraj is the last student on the right
Sumit, 15th from the right, is then \(20-15+1=6\)th from the left, a different place from Neeraj, so a row of 20 works
So the minimum number of students is 20
