Once a principal catches 3 students for coming late. The principal asked the first boy "why did you come late?" The boy said "my bicycle tyre got punctured". Then the principal asked the second boy "why did you come late?" The second boy also said "my bicycle tyre punctured". Then the principal asked the third boy why he had come late and the boy also said what the other 2 boys said. Then the principal said "How come all 3 of you have the same excuse? "Then all the 3 boys replied together "we ride on the same bicycle".