(a) 40 sec
(b) 42 sec
(c) 45 sec
(d) 48 sec
Formula for converting from km/hr to m/s: X km/hr = (X x 5/18) m/s.
Therefore, Speed = (45 x 5/18) m/sec = (25/2) m/sec.
Total distance to be covered = (360 + 140) m = 500 m.
Formula for finding Time = Distance/Speed
Required time = ((500 x 2)/25) sec = 40 sec.