Question

If the speed of a car is reduced by 20% , then it takes 15 minutes more to complete a distance. Generally how many minutes does it take to cover the distance?​

Answer 1

Answer:

Time taken is 1 hour or 60 minutes

Step-by-step explanation:

Let the speed of car be x km/hr

and time taken be t hours

Therefore, distance covered = xt km---------I equation

Now, the speed of car is reduced by 20%

So, new speed = x - [20*x/100] = 4x/5 km/hr

Time taken = t hours + 15 minutes

                   = [t + 1/4] hours

                   = [4t +1/4] hours

distance covered = [4x/5][4t + 1/4} km----------II equation

Equate both the equations,

xt = [4x/5][4t+1/4]

t = 16t+4/20

20t = 16t + 4

4t = 4

t = 1 hour = 60 minutes

                 

                 

Answer 2

Answer:

Step-by-step explanation: original speed 100.New speed 80

speed- 5:4.time-4:5.difference=

5-4=1.for 1 15 mint.for 4 4×15

=60mint