Tiffany left home at 11.25 a.m. and drove towards the suburb. 2 hours later, her younger brother left their home and drove towards the same suburb at 95 km/h. When the younger brother reached the suburb at 4.25 p.m., Tiffany had another 2 km to travel. What was Tiffany’s average speed? Express your answer in mixed number.
Time that the Tiffany's younger brother started driving = 1.25 p.m.
Duration that Tiffany's younger brother drove from 1.25 p.m. to 4.25 p.m. = 3 h

Distance that Tiffany's younger brother travelled
= 3 x 95
= 285 km

Distance that Tiffany travelled by the time her younger brother reached the city
= 285 - 2
= 283 km

Time that Tiffany took to travel 283 km = 5 h

Tiffany's average speed
= 283 ÷ 5
= 56³₅ km/h

Answer(s): 56³₅ km/h