What was the total distance traveled by Mark?

Question

Mark drove at an average speed of 78 kilometers per hour for 45 minutes. He then increased his average speed by 6 kilometers per hour and drove for 20 minutes before reaching home. 

Answer 1

Gonzalo,

 

Mark drove at an average speed of 78 kilometers per hour for 45 minutes (3/4 hour)=>D₁ = 78(3/4)= 58.5 kilometers

increased his average speed by 6 kilometers per hour (78+6=48KPH) and drove for 20 minutes before reaching home (1/3hour) => D₂= 84(1/3)=28 kilometers

Total distance = D₁ + D₂ = 58.5 +28 = 86.5 kilometers