Question

You normally drive on the freeway between San Diego and Los Angeles at an average speed of 105 km/h (65mi/h), and the trip takes 2 hr and 20 min. On a Friday afternoon, however, heavy traffic slows you down and you drive the same distance at an average speed of only 70 km/h (50 mi/h). How much longer does the trip take?

Answer 1

Answer:

Given the second case mentioned, the trip will take:

• 1 hour and 10 minutes more than in the first case, that is, it will take 3 hours with 30 minutes in total.

Explanation:

To calculate how much longer someone will take on that journey, you must calculate the distance traveled, using the aforementioned initial speed, however, the time must be converted into a number that you can calculate, this is done using a rule of three:

• 60 minutes = 1
• 20 minutes = X

• X = 20 minutes / 60 minutes = 0.33333

Now it is calculated:

• Kilometers traveled = 105 km / h (speed used) * 2,333 hours (the change from 2 hours and twenty minutes to a number) = 245 km

Now you just need to divide the total distance by the new speed to find the total time spent now:

• Total time case 2 = 245 Km / 70 Km / h = 3.5 hours (which is equal to 3 hours and 30 minutes)

Since the time of the first case was 2 hours 20 minutes, the difference is 1 hour 10 minutes.

Answer 2

Answer:

3 hours and 28 minutes.

Explanation:

Average speed is gu=iven by,

Average speed = $\frac{Total distance}{Total time}$

∴ Total distance = Average speed × Total time

Average speed = 105 $\frac{km}{h}$

Total time = 2 hour and 20 minutes = 2.33 hour

Total distance = 105 × 2.33

Total distance = 244.65 km

The total distance between San Diego and Los Angeles is 244.65 km.

Due to heavy traffic the average speed is decreased to 70 $\frac{km}{h}$.

Average speed = $\frac{Total distance}{Total time}$

∴ Total time =  $\frac{Total distance}{Average speed }$

Total time = $\frac{244.65}{70}$

Total time = 3.495 hours

Total time = 3 hours and 28 minutes

Thus due to heavy traffic the time taken to travel from between San Diego and Los Angeles is 3 hours and 28 minutes.