Answer:
The van arrived back at Town A at 17:18 (5:18 PM)
Explanation:
Let x be the distance between Towns A and B.
Lets calculate the distance travelled from the first trip to Town B. We have the time travelled and the van's intital speed of 35 km/h. We know that:
Distance(or x)= (Speed)*(Time)
Speed is in units of km/hour, so time must also be in hours. The time between 7:42 and 8:54 is 72 minutes. Convert that to hours using the conversion factor (1 h/60 min)
(72 min)*(1 h/60 min) = 1.2 hour
x = (Speed)*(Time)
x = (35 km/h)*(1.2 h)
x = 42 km [The distance between Towns A and B]
Returning to Town A, the van's speed decreased by 11 km/h. making the speed 24 km/h for the return trip. Use the same calculation as above to calcuate the time for travel on the return from B to A:
Distance = (Speed)*(Time)
We now know the disance, 42 km, and the speed, 24 km/h, so we can solve for time:
Time = (Distance)/(Speed)
Time = (42 km)/(24 km/h)
Time = 1.75 hours or 1 hr and (0.75)*(60 min)
= 1 hr and 45 min
The van left at 15:33 or 15 + 33 minutes
Add the return travel time to the leaving time:
15 hr + 33 minutes
+ 1 hr + 45 minutes
16 hr + 78 minutes
or 17 hr + 18 minutes
The van will arrive at 17:18 (5:18 PM)