Every day Mike leaves his farm at 11:30 a.m. to take a load of potatoes to the chip producers. If he averages 50 km/h he arrives at 1:54 p.m., but if he averages 80 km/h he arrives at 1 p.m. At what speed must he travel to arrive at 12:45 p.m.?
A) 84 km/h
B) 82 km/h
C) 90 km/h
D) 98 km/h
E) 96 km/h
11:30 to 1:54 is 2:24 hr travel time = 2.4 hours
2:4 hr x 50 km/hr = 120 km
120 km/80km/hr = 1.50 hr = 1hr 30 min =~ 1 PM OK....that checks out (this is extraneous info)
11:30 to 12:45 is 1 hr 15 min = 1.25 hr
120 km/1.25 hr = 96 km/hr to arrive at 12:45 PM
11:30 to 1:54 is 2:24 hr travel time = 2.4 hours
2:4 hr x 50 km/hr = 120 km
120 km/80km/hr = 1.50 hr = 1hr 30 min =~ 1 PM OK....that checks out (this is extraneous info)
11:30 to 12:45 is 1 hr 15 min = 1.25 hr
120 km/1.25 hr = 96 km/hr to arrive at 12:45 PM