Question

B)

Answer 1

Answer: 2.5 hours or 150 minutes.

Step-by-step explanation:

We know that she drove a total of 212 km.

And we also need to remember the relationship:

Distance = Time*Speed.

We know that she drove at 42km/h for 20 mins, then the total distance traveled in that time is:

42km/h*(20min)

First we should rewrite the time in hours, we know that:

1 h = 60min

Then:

20 min = 20 min*(1h/60 min) = 0.33 h

Then the equation becomes:

42km/h*(0.33 h) = 13.86km

We also know that she drove at 55km/h for 12 mins at the end, the total distance traveled in this time is:

55km/h*(12 min)

Rewriting the time in hours we get:

12 min = 12 min*(1 h/60min) = (12 /60) h = 0.2 h

Then:

55km/h*(0.2 h) = 11 km

The total distance that we know that she traveled in these two intervals of time is:

11km + 13.86km = 24.86km

The difference between the total distance and this is:

212 km - 24.86km = 187.14 km

Then she drove a total distance of 187.14 km at the speed of 95km/h

The time that it took is:

Time =  (187.14km)/(95km/h) = 1.97 h

Then the total time of the travel is:

1.97h + 0.33h + 0.2h = 2.5 hours

If we want the answer in minutes, we can remember that 1 hour equals 60 minutes, then 2.5 hours are:

2,5 hours = 2.5*60 min = 150 mins