Here’s a question I made up to include on any exam for fire chief, especially in cities with racially troubled fire departments, such as New Haven, Conn., and the District of Columbia:

A truck driven by black firefighters sets out to contain a fire caused by “racial discrimination.” Another driven by white firefighters sets out to save “equal opportunity” from the same fire. The two are on a collision course.

Which truck has the right of way? (Hint: It’s a trick question.)

The answer is: Both trucks have the right of way.

I’ll explain what might seem impossible. But don’t worry if you got it wrong.

On Monday, the Supreme Court ruled that the equal opportunity rights of white firefighters in New Haven had been violated when city officials threw out a promotion test on which no African Americans and two Hispanics qualified for advancement.

Black applicants contended that the test was flawed and racially biased and that the testing process was irrelevant to job performance. But their complaints were narrowly rejected by the court. A conservative majority ruled, in effect, that the white truck had the right of way.

Wrong answer.

For the most part, questions on job promotion tests are kept secret. Even the Supreme Court was clueless about what was on the New Haven firefighter’s test. But let’s not kid ourselves. Many of those tests are known to be outdated, and, more often than not, they do not test relevant skills and behavior.

“One question asked something like, ‘In what direction would your truck be pointed if you set it up to fight a fire in midtown, uptown and downtown,’ “ said Gary Tinney, president of the Firebirds, the New Haven chapter of the International Black Professional Fire Fighters Association. Tinney, a lieutenant, was among the blacks who took the test for captain. “That question doesn’t apply in New Haven. That comes from a New York Fire Department exam. But that’s what you’re dealing with: a network of firefighters that mimic each other so much, pass information between themselves. It happens in the good-old-boy network.”

Then there’s the cheating.

In April, D.C. officials began investigating allegations that rescue workers cheated on a certification exam for emergency medical technicians at a Maryland testing facility. Internal affairs investigators are looking into whether fire department personnel brought in “outside materials,” meaning cheat sheets or textbooks, to help them pass tests.

A scheme that has been uncovered in more than few fire departments involves sending in test takers who aren’t up for promotion but who memorize questions, get together afterward and assemble a complete test that is passed on to a favored few.

If other organizations — the Army, for instance — can come up with relatively fair-minded ways of evaluating and promoting its members, why can’t fire departments? There is no excuse.

Black firefighters in New Haven should have been able to challenge the test. And if the test was racially biased, they should have been compensated with money and promotions. That does not mean that qualified white firefighters should be punished. They passed the tests; they earned their promotions.

If the rules are found wanting, change them before the next tes

Justice Antonin Scalia said of the New Haven case: “The war between disparate impact and equal protection will be waged sooner or later, and it behooves us to begin thinking about how — and on what terms — to make peace between them.”

So, how can the two firetrucks, one black and one white, avoid that collision without one of them yielding the right of way? They stop when they meet. That’s where the fire is. And they must work together to put it out.