Find the total distance ling traveled.

Question

Ling drove at an average speed of 78 kilometers per hour for 45 minutes. She then increased her average speed by 6 kilometers per hour and drove for 20 more minutes before reaching home.

Answer 1

45 minutes = 45/60 of an hour = 3/4 hours

 

(78 km/hr)(3/4 hr) = 234/4 = 58.5 km

 

20 minutes = 20/60 of an hour = 1/3 hours

 

(84 km/hr)(1/3 hours) = 28 km

 

she drove a total of 58.5+28 = 86.5 km

Answer 2

Distance = Rate x Time

Part 1

Distance = 78 kmh x 45 min or 78 kmh x .75 hr

Distance = 58.5

Part 2

Ling drives Distance = 84 kmh x .33 hr

Distance = 27.72

Total Distance = 58.5 + 27.72 = 86.22 kilometers