A train takes 45 minutes to cover a certain distance at a speed of 80 km/h. If the speed is increased by 125%, then how long will it take the train to cover $\frac{8}{5}$ of the same distance?
Answer & explanation
Correct answer: option 3
Distance = Speed × Time
= 80 × \(\frac{45 }{60}\)
= 60 km
125 % = \(\frac{5 }{4}\)
Original Speed : New Speed
4 : 9
4R = 80 km/h
R = 20 km/h
New speed , 9R = 9 × 20 = 180 km/h
\(\frac{8 }{5}\)th of distance = 60 × \(\frac{8}{5}\) = 96 km
Time = \(\frac{96}{180}\) × 60
= 32 minutes