Gwen left home at 11.45 a.m. and drove towards the countryside. 2 hours later, her auntie left their home and drove towards the same countryside at 88 km/h. When the auntie reached the countryside at 4.45 p.m., Gwen had another 5 km to travel. What was Gwen’s average speed? Express your answer in mixed number.
Time that the Gwen's auntie started driving = 1.45 p.m.
Duration that Gwen's auntie drove from 1.45 p.m. to 4.45 p.m. = 3 h

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

Distance that Gwen travelled by the time her auntie reached the city
= 264 - 5
= 259 km

Time that Gwen took to travel 259 km = 5 h

Gwen's average speed
= 259 ÷ 5
= 51⁴₅ km/h

Answer(s): 51⁴₅ km/h