Multiple choice

If a truck travels a distance of 640 km in 12 hours, partly at a speed of 60 km/hr and partly at 40 km/hr, then find the distance that cover with 60 km/hr.

  1. 120 km

  2. 240 km

  3. 360 km

  4. 420 km

  5. 480 km
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let time at 60 km/hr be t hours. Then time at 40 km/hr = (12-t) hours. Total distance: 60t + 40(12-t) = 640. Solving: 60t + 480 - 40t = 640, so 20t = 160 and t = 8 hours. Distance at 60 km/hr = 60 × 8 = 480 km.

Keep practicing — related questions