Answer: 2.87 hours
Step-by-step explanation:
There may be a typo in the question because 55 hours in a day is not logical so you must have meant 5.5 hours.
In that case, the hours he will require on the third day would require the distance left to calculate. Get this distance from the first 2 days.
Day 1 distance travelled = Time * Speed
= 5.5 * 66
= 363 miles
Day 2 distance travelled = Time * Speed
= 5.5 * 58
= 319 miles
Total distance remaining
:= 840 - 363 - 319
= 158 miles
Travelling at 55 miles per hour, the time to be taken is:
= Distance remaining / Speed
= 158 / 55
= 2.87 miles per hour
