Question: Tina has to appear for an exam on 8th of January in Jamshedpur and she can start from her residence in Jamshedpur only after 16:00 hrs of the same day. Choose the option, from the options given below, that will help her to minimize the total time out of Jamshedpur.
Explanation:
Tina cannot leave before 16:00 hours on 8th January. So, if any of the travel modes necessitate departure before 16:00 hours, she will have to start the journey on 9th January. However, keep in mind that the “time out of Jamshedpur” is to be minimized. So, the time that she spends in Jamshedpur till her departure on 9th January cannot be considered “waiting time”.
Consider each option.
Option 1:
Since there are 2 train journeys,
Travel time = (2 × 10) + (2 × 35) + Actual travel in 12443 + Actual travel in 12444 = 20 + 70 + 1120 + 1035 = 2245 minutes
Work time = 360 minutes.
If she goes by train 12443, she will depart on 9th January, reach the work site at 11:10 hours on 10th and finish the work at 17:10 hours. Because train 12444 departs at 17:20 hours, she will miss it and will have to catch it on 11th January. This means a waiting time till 16:45 hours of 11th January i.e. 1415 minutes
So, total time = 2245 + 360 + 1415 = 4020 minutes.
Option 2:
She goes by train and returns by flight
Travel time = Time from home to Jamshedpur station + Actual train travel + Time from Delhi railway station to work site + Flight time = 10 + 1120 + 35 + 435 = 1600 minutes
Work Time = 360 minutes
If she goes by train 12443, she will depart on 9th January, reach the work site at 11:10 hours on 10th and finish the work at 17:10 hours. Flight AI 9809 departs at 05:50 hours on 11th January. So, she will have to wait till 03:20 hours of 11th January i.e. a waiting time of 610 minutes
So, total time = 1600 + 360 + 610 = 2570 minutes.
Hence, option (a) can be eliminated.
Observe that options 3 and 4 can straightaway be eliminated as the mention a return journey by train 12801, which is not possible as that train travels from Jamshedpur to Delhi and not the other way round.
Hence, options 3 and 4 can be eliminated.
Option 5:
She travels both ways by flight.
Travel time = 435 × 2 = 870 minutes
Work Time = 360 minutes
If she goes by AI 9810, she departs on 9th January, reaches the work site at 11:15 hours on 9th and finishes the work at 17:15 hours. Flight AI 9809 departs at 05:50 hours on 10th January. So, she will have to wait till 03:20 hours of 11th January i.e. a waiting time of 605 minutes
So, total time = 870 + 360 + 605 = 1835 minutes.
Hence, option (b) can be eliminated.
Hence, option (e).