A bus and a Lamborghini started travelling from Town X to Town Y at the same time. After 6 hours, the Lamborghini reached Town Y while the bus covered only ⁷₉ of the journey. The speed of the bus was 28 km/h less than the speed of the Lamborghini. Find the speed of the Lamborghini.
Extra distance covered by the Lamborghini in 6 h
= 6 x 28
= 168 km

When the Lamborghini reached Town Y:
Distance covered by the Lamborghini = 9 u
Distance covered by the bus = 7 u

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

2 u = 168

1 u = 168 ÷ 2 = 84

Distance covered by the Lamborghini when it reached Town Y
= 9 u
= 9 x 84
= 756 km

Speed of the Lamborghini
= 756 ÷ 6
= 126 km/h

Answer(s): 126 km/h