ASVAB (Armed Services Vocational Aptitude Battery)Arithmetic Reasoning (AR)Hard
A team of 4 mechanics can service a fleet of vehicles in 15 hours. If the maintenance schedule requires the fleet to be serviced in 10 hours, how many additional mechanics, working at the same rate, are needed?
- A6 additional mechanics
- B2 additional mechanics
- C3 additional mechanics
- D10 additional mechanics
Show answer & explanationAnswer & explanation
Correct answer: B. 2 additional mechanics
This is an inverse proportion problem. The total 'work units' (mechanics * hours) remain constant. Calculate total work units, then divide by the new time to find the required number of mechanics. Finally, subtract the initial number of mechanics.
Why the other options are wrong
- A. This option is incorrect; it represents the total number of mechanics needed, not the *additional* ones.
- C. This option is incorrect; it might result from incorrect calculation of total work or a misstep in finding additional mechanics.
- D. This option is incorrect; it might result from a direct proportion assumption or calculation error.
Inverse Proportion (Work)
In inverse proportion problems involving work, the product of the number of workers and the time taken to complete a task remains constant, assuming all workers operate at the same rate.
- More workers mean less time to complete the same amount of work.
- Formula: Worker1 × Time1 = Worker2 × Time2.
- Used to find an unknown worker count or time.
Memory trick: More hands make light work, so time goes down.