NZDF aptitude questions: one worked example per reasoning type

A numerical ability example

A vehicle uses 8.4 litres per 100 km. How much fuel is needed for a 350 km move?

The method: set the relationship up before calculating. 8.4 litres per 100 km means 0.084 litres per km, so 350 km needs 29.4 litres. The common error is dividing when you should multiply, which an estimate catches instantly: 350 km is three and a half hundreds, so the answer must be around three and a half times 8.4.

Estimate first, calculate second. It eliminates wrong options faster than arithmetic does.

An inductive reasoning example

A sequence of tiles: each has a number of dots and a shape that rotates. What comes next?

The method: check one attribute at a time across the entire sequence. Count the dots first and write the numbers down. Then track rotation separately. Then shading. Two simple rules running in parallel look like one impossible rule if you try to see them at once, that is the whole difficulty of inductive items.

A deductive reasoning example

All members of the section carry a radio. Some members of the section are trained in first aid. Does it follow that some radio carriers are trained in first aid?

Yes, and the reason is worth being precise about. Every section member carries a radio, so the first-aid-trained members are among the radio carriers. The method: work only from what is stated. Deductive items are almost always failed by importing a real-world assumption the question did not give you.

A mechanical reasoning example

Two gears mesh directly. The first turns clockwise. Which way does the second turn?

Anticlockwise: directly meshed gears turn in opposite directions. In a train of three, the first and third turn the same way.

The method: learn the handful of principles that generate most mechanical items: meshed gears reverse, larger driven gears turn slower with more torque, more supporting rope sections mean less force in a pulley system, and a longer lever arm means less effort. Most questions are one of those in a new costume.

What is the difference between inductive and deductive reasoning?

How should you practise each area?

Untimed method work first, then time pressure. Trying to get fast before you are consistent just entrenches whichever approach you happened to start with. Background on how the whole assessment fits together is in the NZDF aptitude test guide.