The ratio between the speed of a bus and train is 15 : 27 respectively. Also, a car covered a distance of 720 km in 9 hours. The speed of the Bus is three-fourth the speed of the car. How much distance will the train cover in 7 hours?

Answer: Option B

Ratio of speed of Bus and Train = 15 : 27
Let speed of the bus is 15X and Speed of the Train is 27X
Car Covered 720 km in 9 hours.
So, Speed of the Car = $$\frac{720}{9}$$  = 80 kmph
Given, Speed of the bus is $$\frac{3}{4}$$ of Car, So speed of the Bus,
= $$\frac{80\times 3}{4}$$   = 60 kmph
Thus,
15X = 60
X = 4
So, Speed of the train = 27X = 27 × 4 = 108 kmph.
Hence, Train will cover distance in 7 hours,
= 108 × 7
= 756 km