Algebra problem

Question

Shayna left the airport and drove toward the capital at an average speed of 52 km/h. Sometime later Mei left driving in the same direction but at an average speed of 65 km/h. After driving for four hours Mei caught up with Shayna. Find the number of hours Shayna drove before Mei caught up.

Answer 1

Hi Mackenzie, this is an application of the D(istance) = R(ate) * T(ime) equation.

 

Start with Mei.

 

Mei drove for 4 hours at a rate of 65 km/h. Substitute for R, 65 km/h and T, 4 hours, to find D.

 

D = 65 * 4

 

D = 260 kilometers

 

Shayna drove the same distance before Mei caught up. We know D, 260 kilometers, and R, 52 km/h. Solve for T.

 

D = R * T

 

T = D / R

 

T = 260 / 52

 

T = 5

 

Shayna drove for 5 hours before Mei caught up with her.

 

Questions?