Answer: t = 2.52 hours
Step-by-step explanation:
For the first 30 km, the bicyclist rode with a speed of v km/hour.
Speed = distance/time
Time = distance/speed
Time taken to travel 30 km at a speed of v km/hour is
30/v
For the remaining 17 km he rode with a speed which was 2 km/hour greater than his original speed. This means that his speed was v + 2. Time taken to travel 17 km at a speed of v+2 km/hour is
17/(v + 2)
Let t be the time (in hours)
Total time that the cyclist spent on the entire trip would be
t = 30/v + 17/(v + 2)
To find t if v is 18, we will substitute v = 18/in the equation. It becomes
t = 30/18 + 17/(18 + 2) = 30/18 + 17/20
t = 906/360 = 2.52 hours
