There are three trucks A, B, C. A loads 10 kg/min. B loads 13 1/3 kg/min. C…
2024
There are three trucks A, B, C. A loads 10 kg/min. B loads 13 1/3 kg/min. C unloads 5 kg/min. If three simultaneously works then what is the time taken to load 2.4 tones?
- A.
3 hrs
- B.
2 hrs 10 min
- C.
2 hrs
- D.
1 hr
Attempted by 18 students.
Show answer & explanation
Correct answer: B
Solution:
Compute individual rates (kg per minute): A = 10, B = 13 1/3 = 40/3, C (unloading) = 5.
Net loading rate = 10 + 40/3 − 5 = 55/3 kg/min (≈18.333 kg/min).
Total mass = 2.4 tonnes = 2400 kg. Time = 2400 ÷ (55/3) = 2400 × 3/55 = 7200/55 = 1440/11 minutes.
Convert to hours and minutes: 1440/11 = 130 + 10/11 minutes = 130 minutes and 54.545... seconds, which is about 2 hours 10 minutes 54.5 seconds. If rounding to the nearest minute, this is 131 minutes = 2 hours 11 minutes.
Therefore, the closest provided answer is 2 hrs 10 min (the intended choice); the exact time is 1440/11 minutes (≈130.91 minutes).