A train consists of 12 boggies, each boggy 15 metres long. The train crosses a telegraph post in 18 seconds. Due to some problem, two boggies were detached. The train now crosses a telegraph post in	Choose the correct option: A) 18 sec B) 12 sec C) 15 sec D) 20 sec E) None of these
Length of train = 12 × 15 = 180 m.   Then, speed of train = 180⁄18 = 10 m/s   Now, length of train = 10 × 15 = 150m   ∴ Required time = 150⁄10 = 15 sec.   Answer 15 sec
<result>C</result>
A train consists of 12 boggies, each boggy 15 metres long. The train crosses a telegraph post in 18 seconds. Due to some problem, two boggies were detached. The train now crosses a telegraph post in