Problema Solution

A woman cycles 8 miles per hour faster than she runs. Every morning she cycles 4 miles and runs 2.5 miles, for a total of one hour of exercise. How fast does she run?

Answer provided by our tutors

let


x = the speed of running

y = the speed of cycling


a woman cycles 8 miles per hour faster than she runs


y = 8 + x


she cycles 4 miles and runs 2.5 miles, for a total of one hour


4/y + 2.5/x = 1


by solving the system of equations


y = 8 + x

4/y + 2.5/x = 1


we find that


x = 3.78459 miles per hour


y = 11.7846 miles per hour


She runs with a speed of 3.78459 miles per hour.