Winnie left home at 11.45 a.m. and drove towards the city. 2 hours later, her auntie left their home and drove towards the same city at 88 km/h. When the auntie reached the city at 4.45 p.m., Winnie had another 6 km to travel. What was Winnie’s average speed? Express your answer in mixed number.
Time that the Winnie's auntie started driving = 1.45 p.m.
Duration that Winnie's auntie drove from 1.45 p.m. to 4.45 p.m. = 3 h

Distance that Winnie's auntie travelled
= 3 x 88
= 264 km

Distance that Winnie travelled by the time her auntie reached the city
= 264 - 6
= 258 km

Time that Winnie took to travel 258 km = 5 h

Winnie's average speed
= 258 ÷ 5
= 51³₅ km/h

Answer(s): 51³₅ km/h