Answer:
1.125 minutes
Explanation:
The train consists of 6 carriages each of length 20 metres
Total Length of Carriages = Number of Carriage X Length Per Carriage =20 X 6
=120 metres
Gap between the carriages= 1 metre each
There are a total of 5 gaps between the carriages = 5X 1= 5m
Therefore Total Length of the train= Total Carriage Length + Total Gap Length
= 120+5= 125 metres
Total Distance Required o Cross the Tunnel= 1km + 125 metres
= 1.125km
The Speed of the Train = 60km/hr
Time Required = Distance /Speed
= 1.125/60= 0.01875 hours
We can convert the hour to minutes by multiplying by 60
0.01875 hours = 0.01875 X 60 minute = 1.125 minutes
Therefore the train requires 1.125 minutes to cross the tunnel.