More about equations

Question

Sam runs from town A to town B which are 20km apart. It is given that Sam runs with a constant speed in the first 12km,then his speed decreases by 5km/h in the last 8km. If the total time spent by Sam is 1hour and 8minutes ,find his speed in the first 12km.

Answer 1

Hey Nina,

This will help you get started:

t₁+t₂ = total time

d₁/r₁+d₂/r₂ = total time

12/r₁+8/(r₁-5) = 17/15 <--- You must solve for r₁ using this equation.

I am available for one-on-one help. Don't be afraid to ask!