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?

1 answer

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.