Correct Anaswer : 4
Explanation:
"For (10 + A + B) = 12 stations, no of tickets required. when 4 new stations are added for one way journey = 12 x 4 = 48 Also, each 4 new stations require (16 - 1) = 15 new tickets for one way journey. No. of tickets for 4 new stations = 15 x 4 = 60 Hence,"