What the ASVAB is actually testing
Rate, distance, and time questions always give you two of the three variables and ask you to find the third. The test frames them as vehicle speeds, running pace, or work rates — but the underlying formula is the same every time: Distance = Rate × Time.
The reason recruits miss these isn't the formula — it's unit mismatch or the round-trip average speed trap.
D = R × T: know all three forms
Cover the variable you're solving for with your thumb and the remaining two show you the operation:
- Cover D → multiply R × T
- Cover R → divide D by T
- Cover T → divide D by R
That's it. The formula never changes. Only the variable you're solving for changes.
The round-trip trap
This is the most commonly missed rate question on the ASVAB. If you travel the same distance at two different speeds, your average speed is not the average of the two speeds.
The right approach: find the actual total time for each leg, add them, then divide total distance by total time. See worked example 3. The shortcut answer of (6 + 4) ÷ 2 = 5 mph is wrong.
Work-rate problems: same formula, different framing
"How long does it take two people working together?" These use the rate formula too — but "rate" means fraction of the job completed per hour. Add the individual rates to get the combined rate, then flip it to get total time.
Worker A at 1/6 job/hr + Worker B at 1/3 job/hr = 1/2 job/hr combined → 2 hours total.
Unit consistency
If speed is given in miles per hour but time is given in minutes, convert before plugging in. 30 minutes = 0.5 hours. Missing this step leads to off-by-factor-of-60 errors that will show up as a plausible-looking wrong answer choice.