SOLUTION: Anna drives 45 km to work. If she increases her usual average speed by 5 km/h, the time it takes her to drive to to work is decreased by 6 minutes. Find her usual speed
Algebra ->
Customizable Word Problem Solvers
-> Travel
-> SOLUTION: Anna drives 45 km to work. If she increases her usual average speed by 5 km/h, the time it takes her to drive to to work is decreased by 6 minutes. Find her usual speed
Log On
Question 1167532: Anna drives 45 km to work. If she increases her usual average speed by 5 km/h, the time it takes her to drive to to work is decreased by 6 minutes. Find her usual speed Answer by ikleyn(52775) (Show Source):
Use and solve this "time" equation
- = of an hour (= 6 minutes).
It is equivalent to
- = 1 (1)
and has an obvious solution x = 45.
CHECK. - = - = 10 - 9 = 1. ! Correct !
Alternatively, you can reduce the equation (1) to quadratic equation and solve it formally.
