Winnie left home at 11.40 a.m. and drove towards the countryside. 2 hours later, her father left their home and drove towards the same countryside at 89 km/h. When the father reached the countryside at 4.40 p.m., Winnie had another 5 km to travel. What was Winnie’s average speed? Express your answer in mixed number.
Time that the Winnie's father started driving = 1.40 p.m.
Duration that Winnie's father drove from 1.40 p.m. to 4.40 p.m. = 3 h

Distance that Winnie's father travelled
= 3 x 89
= 267 km

Distance that Winnie travelled by the time her father reached the city
= 267 - 5
= 262 km

Time that Winnie took to travel 262 km = 5 h

Winnie's average speed
= 262 ÷ 5
= 52²₅ km/h

Answer(s): 52²₅ km/h