If a train travels 180 km at a speed of 60 km/h ,how much less time will it take to complete the same journey at a speed of 70 km/h?
Trick: Time saved = (Distance × Speed difference) ÷ Product of speeds
Distance = 180 km
Speed difference = 70 − 60 = 10 km/h
Time saved = (180 × 10) ÷ (60 × 70)
= 1800 ÷ 4200
= 3/7 hour
Convert to minutes:
3/7 × 60 = 25.71 minutes
Answer: Approximately 25 minutes 43 seconds less.=26min