24hrs
They are 1677 kilometers from Mumbai (Bombay) to Calcutta (Kolkata)
3
Not much
3 hours
Bombay or now known as Mumbai
You can go by air, it takes just an hour and 40mins or you could take the train too but that would take about 25hrs or even a bus with many stop-overs. Distance between Delhi to Mumbai is 1402 Kilometre, Mumbai is well connected by air, train and road. Flight take 1 hour 50 minute, by road travel time is 26 hour and by train you can reach in 16 to 30 hours (depend on train type) Source : roaddistance.in/new-delhi/delhi-new-delhi-to-mumbai-distance/by-road/
24 hours
Total 18 platforms. That is 1 to 7 suburban train platforms and 8 to 18 mainline train platforms.
6 hours
Around 4.5 hours by bus and around 2:15 hours by train.
Approximately 18 Hours on a Direct Flight
About 3 hours.