Answer:
The car must go at 108 km per hour
Step-by-step explanation:
Let us solve the question
∵ A journey by bus takes 45 minutes at 60 km per hour
∴ The speed of the bus = 60 km per hour
∴ The time of the journey = 45 minutes
→ Change the time from minutes to hours
∵ 1 hour = 60 minutes
∴ 45 minutes = 45 ÷ 60 = 0.75 hour
∴ The time of the journey = 0.75 hour
∵ Distance = Speed × Time
→ Substitute the speed by 60 and the time by 0.75
∵ The distance that the bus traveled = 60 × 0.75
∴ The distance that the bus traveled = 45 km
∵ A car goes to do the same journey in 25 minutes
∴ The distance that the car travels = 45 km
∴ The time that the car takes = 25 minutes
→ Divide it by 60 to change it to hours
∵ 25 minutes = 25 ÷ 60 = [tex]\frac{5}{12}[/tex] hour
∴ The time that the car takes = [tex]\frac{5}{12}[/tex] hour
→ Use the rule of the distance above to find the speed of the car
∵ 45 = the car's speed × [tex]\frac{5}{12}[/tex]
→ Divide both sides by [tex]\frac{5}{12}[/tex]
∴ 108 = the car's speed
∴ The car's speed = 108 km per hour
∴ The car must go at 108 km per hour
