Question

Annette drives her car 105 miles and has a mean of a certain speed. if the mean speed had been 4mph more, she could have traveled 119 miles in the same length of time. what was her mean speed?

Answer 1

Let the mean speed be x mi/hr
Time taken to travel will be:
distance/ speed
thus:
105/x=119/(x+4)
solving for x we get:
105(x+4)=119x
105x+420=119x
119x-105x=420
x=30 mi/hr
Thus the mean speed is 30 mi/hr