Question

Sally left Tampa traveling 66 mph. Keith, to catch up, left some time later driving at 75 mph. Keith caught up after 8 hours. How long was Sally driving before Keith caught up?

Answer 1

9.1 hours

Explanation:

Given

Sally

Speed = 66mph

Keith

Speed = 75mph

Time = 8 hours

Required

Determine how long Sally has traveled

To solve this, we make use of Speed formula.

Speed = Distance/Time

Make Distance the subject of formula

Distance = Speed * Time

For Sally:[Substitute 66mph for speed]

Distance = 66 * Time ------ Equation 1

For Keith [Substitute 75mph for speed and 8 hours for Time]

Distance = 75 * 8

Distance = 600m----- Equation 2

From the question, we understand that Keith caught up; this implies that they've both traveled the same distance.

Hence;

Equation 1 = Equation 2

66 * Time = 600

Time = 600/66

Time = 9.1 hours

Hence, Sally has traveled 9.1 hours