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 Friday, if the ratio of speed of boat to speed of stream is 2 ∶ 1, then what is the difference between the time taken by the boat to go upstream and to go downstream?
1
36 hours
2
42 hours
3
45 hours
4
35 hours