Comprehension Passage
The following table shows the distance travelled by a boat moving upstream (in km) during five different days of a week from Monday to Friday, along with the speed of boat (in km/hour), speed of stream (in km/hour) and total time taken (in hours). Some data is missing in the table (indicated as "-") that you are expected to calculate, if required. Based on the data in the table, answer the questions that follow.
Day - Wise Distance covered by a Boat and other Details
| Days | Distance Upstream(km) | Speed of Boat (km/hour) | Speed of Stream (km/hour) | Total TimeTaken (hours) |
| Monday | 320 | - | 4 | - |
| Tuesday | - | - | - | 75 |
| Wednesday | 270 | - | 6 | - |
| Thursday | - | 11 | 7 | - |
| Friday | 324 | - | - | 72 |
Note : (1) Distance Upstream = Distance Downstream, if not stated otherwise
(2) Total Time Taken = Downstream Time + Upstream Time
On Monday, if the difference between the time taken by the boat to go upstream and to go downstream is 20 hours, then what is the total time taken by the boat to go upstream and downstream?
1
40 hours
2
30 hours
3
80 hours
4
60 hours