The JobCannon test has 25 questions and an estimated 9 minutes. That is about 22 seconds per question, which is enough for a one-step problem and tight for a three-step one. How you spend it matters more than how fast you read.
What 22 Seconds Buys
Treat 22 seconds as an average, not as a limit on each question. A one-step question, such as a single gear ratio or a balanced lever, can be done in well under the average once you have the rule in your head. A compound gear train or a lever with three loads takes longer. The average only works if the quick ones pay for the slow ones.
So the first five seconds of any question are for one decision: is this a one-step or a multi-step problem? Then you know how much of the clock you are allowed to spend.
Where the Time Actually Goes
- Reading: finding the pivot, the driver or the supporting ropes. Read once, then mark them on your paper.
- Setup: naming the trade and writing the rule. This is the step to protect, because a wrong setup cannot be rescued by fast arithmetic.
- Arithmetic: keep the numbers simple. Test numbers are usually chosen so that the division comes out exact, and if it does not, suspect a flipped ratio.
- Checking: five seconds on size and direction, as in the four-step routine.
Two Checkpoints
Use two checkpoints and nothing more complicated. Halfway through the time (4.5 minutes) you should be about halfway through the questions, which is question 13. Two thirds through the time you should have passed question 17.
If you are behind at a checkpoint, do not speed up everything. Skip the next multi-step question on first pass and come back to it if you have time.
When to Move On
A useful rule: if you have spent twice the average, about 44 seconds, and still have no rule written on your paper, stop. Eliminate the options that fail the size-and-direction check, choose the best of what is left, and move on.
A question you cannot start is almost never solved by staring at it. A fresh look after two or three other questions often shows the pivot or the rope you missed.
A Sample Pacing Plan
Here is one way to use 9 minutes on 25 questions. It is a plan to adapt, not a rule.
- First pass, about 6 minutes: work through the questions in order. Answer each one you can set up straight away. Mark any that need more than about 44 seconds and move on.
- Second pass, about 2.5 minutes: return to the marked questions. Use the elimination check first, then the full routine.
- Last 30 seconds: make sure every question has an answer.
Pacing Traps
- Over-investing in question one. Spending too long on the first question because it is the first is an easy way to lose the clock before you have met the easier ones.
- Rushing the setup to save time. A fast wrong setup costs the whole question; a slow right one costs a few seconds.
- Redoing finished work. One size-and-direction check is enough. A second full recalculation is time better spent on the next question.
- Leaving blanks. If a wrong answer scores nothing, a blank scores nothing too. Eliminate what you can and choose.
How to Practise Pacing
- Learn each machine untimed first. Pace comes after accuracy.
- Then do full sets against the clock: 25 questions in 9 minutes.
- After each set, mark every question where you went over twice the average, and note whether the cause was reading, setup or arithmetic.
- Spend your next session on the cause that came up most.
The JobCannon mechanical reasoning test gives you a full set to time yourself on. For a day-by-day plan, see how to prepare for a mechanical reasoning test in two weeks.