OAR Practice Test

What the real test usually looks like

The OAR (Officer Aptitude Rating) is part of the Aviation Selection Test Battery, series E (ASTB-E), which the Naval Aerospace Medical Institute runs for the US Navy, Marine Corps and Coast Guard. Aviation applicants take the whole battery. Applicants to other officer programs, such as Navy Officer Candidate School (OCS), may need only the OAR; the Navy advises asking your recruiter which you need (ASTB-E FAQ).

Three subtests. The Navy's overview page describes them (ASTB-E overview):

• Math Skills Test (MST): arithmetic and algebra with some geometry, as equations and word problems: solving for variables, time and distance, simple probability, fractions, roots, exponents, angles, areas and perimeters.
• Reading Comprehension Test (RCT): passages where you choose the one option that can be inferred from the passage itself. Wrong options may still look true.
• Mechanical Comprehension Test (MCT): introductory high school physics: gases and liquids, engines, electricity, gears, weight distribution, and simple machines such as pulleys and fulcrums.

Adaptive, with no going back. The FAQ says these subtests are computer adaptive, delivered through a system called APEX: a right answer is usually followed by a harder question and a wrong one by an easier question, so the number and difficulty of questions vary. You cannot skip a question, go back, or change an answer.

About 1 to 2 hours, no calculator. The FAQ says the OAR takes 1 to 2 hours on APEX. The Navy publishes no fixed question count, because the subtests adapt. The math is designed to be done without a calculator; relevant formulas are provided and you get scrap paper.

What our practice covers. Our full mocks are in the style of the OAR: the three subtests, timed, one question at a time with no going back. Where the real subtests adapt, ours have a fixed length, the same for everyone. The rest of the ASTB-E (aviation and nautical knowledge, a personality inventory and performance tasks) is not included. For more levers, gears and pulleys, see our mechanical aptitude test.

Question types with worked examples

One worked example for the main kinds of OAR-style question, with the trap to avoid.

1. Math Skills: time and distance. A ship sails at 15 knots. How long does 75 nautical miles take? Time is distance divided by speed: 75 / 15 = 5 hours. Trap: multiplying instead of dividing. Write distance = speed x time first, then fill in what you know.

2. Math Skills: solving for a variable. If x / 3 + 4 = 10, what is x? Take 4 from both sides: x / 3 = 6, so x = 18. Check by putting it back: 18 / 3 + 4 = 10.

3. Math Skills: roots, exponents and shapes. What is the square root of 144 plus 2 cubed? 12 + 8 = 20. Know the areas of a rectangle, a triangle (half base times height) and a circle (π r squared), and that a triangle's angles add up to 180°. Formulas are provided, but knowing them saves time.

4. Reading Comprehension: what can be inferred. Passage: "The dining hall serves breakfast from 6 to 8 a.m. on weekdays and from 7 to 9 a.m. on weekends." Someone arriving at 8:30 a.m. on a Saturday can still eat. Trap: an option like "breakfast is the busiest meal" sounds reasonable, but the passage never says it. Choose what the text proves.

5. Mechanical Comprehension: gears. A 12-tooth gear drives a 36-tooth gear at 90 turns a minute. How fast does the large gear turn? Three times the teeth, a third of the speed: 30 turns a minute, in the opposite direction. Each mesh reverses the direction.

6. Mechanical Comprehension: pressure in liquids. Two tanks, one wide and one narrow, hold water to the same depth. Which has more pressure at the bottom? Neither. Pressure in still liquid depends on depth, not on width. Trap: picking the wide tank because it holds more water.

7. Mechanical Comprehension: electricity. Two 6-ohm resistors in series sit across a 12-volt battery. What current flows? In series resistances add, to 12 ohms, and current = voltage / resistance = 1 ampere.

How to prepare

1. Confirm which test you need. Aviation applicants take the full ASTB-E; many other officer programs need only the OAR. Your recruiter can tell you.
2. Practice math by hand. No calculator is allowed, so work fractions, percentages, equations, exponents and roots on paper.
3. Learn the mechanical basics. Levers (weight times distance), pulleys, gears, pressure in liquids, flow in pipes and simple circuits come up again and again.
4. Read for proof. For each reading answer, find the sentence that supports it. If you cannot point to one, it is probably a trap.
5. Commit to each answer. You cannot go back, so read fully, eliminate what you can, choose and move on.
6. Work briskly, and do not guess wildly at the end. The Navy says unanswered questions on an adaptive subtest can bring a score penalty, but that random guessing as time runs out usually costs more (ASTB-E FAQ). Our free sample allows about 64 seconds a question, a steady rhythm to practice.
7. Take full timed mocks. Three subtests in a row is tiring. A whole mock once or twice before test day helps you hold focus to the end.
8. Retest only when ready. Attempts are limited, and your most recent score replaces earlier ones, even a higher one.

How scoring usually works

One score from 20 to 80. The Navy's overview page says people who take only the OAR receive one score, from 20 to 80 in one-point steps, used to predict academic performance at Navy Officer Candidate School (ASTB-E overview).

Adaptive scoring. The FAQ says the difficulty of the questions you answered is taken into account, so people who saw different questions can be compared, and that leaving too many questions unanswered when time runs out can bring a penalty.

Minimum scores. The Navy says requirements differ by program and service. We do not quote a passing score, because none applies to everyone and requirements can change. Ask your recruiter.

Retests. The overview allows no more than three attempts at the current OAR or ASTB-E and sets a wait of 30 full calendar days before an ASTB-E retest; ask your recruiter how that applies to an OAR-only retake. The FAQ says your most recent attempt becomes your score of record, even if an earlier one was higher.

Our practice score is the number of our own questions you got right, with a breakdown by subtest. It is a practice score, not an OAR score, and it does not predict a score on the 20 to 80 scale.

How this practice compares with the real test

What we match. Math skills, reading comprehension and mechanical comprehension, timed, one question at a time with no going back and no calculator. Every answer is explained.

What we do not include. The rest of the ASTB-E, and adaptive question selection: each of our mocks has a fixed length.

What we cannot match. The OAR's questions and scoring formulas belong to the Navy, which does not release the formulas. Our questions are original, in a similar style. We cannot give you an OAR score, and Intellect Council is not affiliated with the US Navy or the Naval Aerospace Medical Institute.

A one-week OAR study plan

• Day 1: Take the free sample above. Note which subtest cost you the most.
• Day 2: Math skills: equations, fractions and time and distance problems, by hand.
• Day 3: Mechanical comprehension: levers, pulleys and gears, then fluids and circuits.
• Day 4: Reading comprehension: for each answer, point to the sentence that proves it.
• Day 5: A full timed mock. The 30-Day Pass includes full OAR-style mocks, each with explanations.
• Day 6: Review every miss, and redo your weakest subtest.
• Day 7: A second mock in the morning, then rest. The Navy's FAQ asks you to bring photo ID and proof of your Social Security number.