jmc

Question

Jeremy's father drives him to school in rush hour traffic in 20 minutes. One day there is no traffic, so his father can drive him 18 miles per hour faster and gets him to school in 12 minutes. How far in miles is it to school?

Accepted Answer

For starters, we identify d as distance and v as velocity (speed) Writing the equation gives us: dv=13 and dv+18=15. This gives d=15v+3.6=13v, which gives v=27, which then gives d=9.