Question

A car travels the first 20km in 2hrs. How much time should it take to travel the next
40km so that its average speed remains 15km/hr.​

Answer 1

Answer:

The required time is 2 hours

Explanation:

Given :

A car travels the first 20 km in 2 hrs.

To find :

the time taken by the car to travel the next 40 km so that the average speed remains 15 km/hr

Solution :

Let the time taken to travel the next 40 km be 't' hours

we know that,

➟ Average speed = total distance travelled/total time taken

➣ Total distance travelled

= 20 km + 40 km

= 60 km

➣ Total time taken

= 2 hrs + t hrs

= (2 + t) hours

Substituting the values,

15 km/hr = 60 km/(2 + t) hours

15 = 60/(2 + t)

15(2 + t) = 60

 30 + 15t = 60

  15t = 60 - 30

  15t = 30

   t = 30/15

   t = 2 hours

∴ The time taken to travel the next 40 km is 2 hours