In a 4 mile walk, Jenny covered the first 2 mile in 40 minutes. How fast should she walk the rest of the way to average 3.5 miles per hour overall?

d = V*T = 4 mi.

3.5*T = 4.
T = 1.143 h. To walk the 4 miles.

1.143 - 40/60 = 0.476 h. To walk the last 2 miles.

V = 2mi/0.476h = 4.2 mi/h. = Speed for
last two miles.

To answer this question, we first need to calculate how much time Jenny has left to cover the remaining 2 miles.

Jenny covered the first 2 miles in 40 minutes, which means she has 60 - 40 = 20 minutes left to cover the remaining 2 miles.

Next, we need to convert the remaining time from minutes to hours, as we want the average speed in miles per hour. Since there are 60 minutes in an hour, we can divide the remaining time of 20 minutes by 60 to get the time in hours: 20 / 60 = 1/3 hours.

Now, we can calculate how fast Jenny should walk the remaining 2 miles in this time to average 3.5 miles per hour overall.

We know that Jenny needs to cover a total of 4 miles in 1 hour (since 3.5 miles per hour is the desired average speed). She has already covered 2 miles in 40 minutes, which is 2/3 hours.

So, she has 1 hour - 2/3 hours = 1/3 hours to cover the remaining 2 miles.

We can use the formula: speed = distance / time to find the required speed.

speed = 2 miles / (1/3 hours) = 2 / (1/3) = 6 miles per hour.

Therefore, Jenny needs to walk the remaining 2 miles at a speed of 6 miles per hour to average 3.5 miles per hour overall.