At 4.20 p.m., Betty and Bobby left Hotel V for Hotel W at average speeds of 70 km/h and 54 km/h respectively. Upon reaching Hotel W, Betty rested for 10 minutes. She then headed back for Hotel V at an average speed of 70 km/h along the same route. Bobby and Betty met each other on their way at 8 p.m.

1. How much more distance had Betty covered than Bobby when they met on their way?
2. How far apart were Hotel V and Hotel W? Express your answer in mixed number.

(a)
Duration from 4.20 p.m. to 8 p.m. = 3 h 40 min = 3²₃ h
Duration from 4.20 p.m. to 8 p.m. without 10 min rest = 3 h 30 min = 3¹₂ h

60 min = 1 h
40 min = ⁴⁰₆₀ = ²₃ h
30 min = ³⁰₆₀ = ¹₂ h


Distance covered by Betty
= 70 x 3¹₂
= 70 x ⁷₂ 
= 245 km

Distance covered by Bobby
= 54 x 3¹₂
= 54 x ⁷₂
= 198 km

Distance that Betty covered more than Bobby
= 245 - 198
= 47 km

(b)
Distance between Hotel V and Hotel W
= (245 + 198) ÷ 2
= 443 ÷ 2
= 221¹₂ km

Answer(s): (a) 47 km; (b) 221¹₂ km