Shannon left home at 10.25 a.m. and drove towards the town. 3 hours later, her grandmother left their home and drove towards the same town at 96 km/h. When the grandmother reached the town at 5.25 p.m., Shannon had another 6 km to travel. What was Shannon’s average speed? Express your answer in mixed number.
Time that the Shannon's grandmother started driving = 1.25 p.m.
Duration that Shannon's grandmother drove from 1.25 p.m. to 5.25 p.m. = 4 h

Distance that Shannon's grandmother travelled
= 4 x 96
= 384 km

Distance that Shannon travelled by the time her grandmother reached the city
= 384 - 6
= 378 km

Time that Shannon took to travel 378 km = 7 h

Shannon's average speed
= 378 ÷ 7
= 54 km/h

Answer(s): 54 km/h