A lorry and a Lamborghini started travelling from Town S to Town T at the same time. After 3 hours, the Lamborghini reached Town T while the lorry covered only ⁷₉ of the journey. The speed of the lorry was 28 km/h less than the speed of the Lamborghini. Find the speed of the Lamborghini.
Extra distance covered by the Lamborghini in 3 h
= 3 x 28
= 84 km

When the Lamborghini reached Town T:
Distance covered by the Lamborghini = 9 u
Distance covered by the lorry = 7 u

Extra distance covered by the Lamborghini 
= 9 u - 7 u
= 2 u

2 u = 84

1 u = 84 ÷ 2 = 42

Distance covered by the Lamborghini when it reached Town T
= 9 u
= 9 x 42
= 378 km

Speed of the Lamborghini
= 378 ÷ 3
= 126 km/h

Answer(s): 126 km/h