If Atul finds that he is twelfth from the right in a line of boys and fourth from the left, how many boys should be added to the line such that there are 28 boys in the line ?

Answer: B. 13
Clearly, number of boys in the line = (11 + 1 + 3) = 15. .'. Number of boys to be added = 28 - 15 = 13.