A quiz: Does public school mean children? Do suburbs mean mainly young families with kids?

The answers to both questions might have been "yes" a few years ago, but watch out, expecially in Arlington County. The adults have invaded.

Arlington's public schools, along with the traditional images of lunchpails, yellow buses and PTA's, have undergone quiet a transformation lately; Adult students are considerably more numerous than the kids. Approximately 23,000 adults attended public schools in Arlington last year, compared with about 16,000 students in Kindergarten through the 12th grade.

If the trend is surprising, it shouldn't be. It is right in line with changes in suburban life over the last decade.

For instance, according to a recent analysis of census studies, all-adult households up slightly more than half the households in suburban Washington. In the close-in suburbs of Arlington and Alexandria, the change has been even more dramatic: About 72 percent of all households have only one or two persons, according to the report by Eunice S. and George Grier of the Greater Washington Research Center.

"Let's face it," said Bill Young, director of Adult, Vocational and Career Education in Arlington, "the community is growing older."

Arlington's adult education program has multiplied eightfold since 1969, when there were 3,000 adult students. At the same time, Arlington's elementary and secondary school enrollments have dropped by a third, nearly three times the areawide a average. e

The surge of adults and their appetites for recreation, self-improvement and job training has put a new focus on continuing education programs, once the stepchild of public school curricula. One result is the major expansion over the last decade; another is that adult education, at least in Arlington, is still trying to establish its own character.

So great has been the interest in continuing education that the Virginia legislature directed each region to study possible overlap between community college and adult education classes.

In Arlington, that has meant coordinating, and sometimes competing with, Northern Virginia Community College.

"We found, yes, there is a duplication," said Young, who helped study the problem in Northern Virginia. "But we decided to continue as we are until the day when one of us alone draws practically all the students . . . With the emphasis on competency-based education, eventually there will be a continuum from adult education to the community college."

One indication of the changing times is the composition of adult classes.

There are still high school dropouts returning for diplomas and homemakers and senior citizens seeking recreation. But, in general, the students are younger, classes are now sprinkled with refugees and other immigrants and there is a greater proportion of adults seeking retraining for a second career.

"Usually when people think of adult education, they think of adult illiteracy programs," said Young, director since 1969. "Our program is one of the more comprehensive in this metropolitan area, and probably in the entire country. It meets the needs of all the adults in this community."

The program also benefits a school system burdened by declining enrollments and empty classrooms. Arlington's adult classes are held in 22 county facilities, many of them surplus schools.

"We're gettting full utilization of the physical plant," said Young in a recent interview in his office at the former Gunston Intermediate School.

The courses, like the students, reflect a variety of interests and needs.

In the clerical courses Louise Nickens teach, a Pakistani student with a degree in political science is learning office skills so she can work while continuing her university education here.

Elderly students at Culpeper Garden sign up for everything from Income Tax Procedure to Auto Mechanics. They pay about $6.50 a course.

"I've had people 80 years old in that auto mechanics class," said Ernest Karl, a retired federal government employe who coordinates the senior adult program. "My wife even took it. They take it to discover the difference between a carburetor and a water tank. It was so popular we started Auto Mechanics II."

Over at Langston Center, a former elementary school on Lee Highway, Edward Hackley is working toward the final eight credits he needs for his high school diploma. He enrolled in the program after losing out on a job because he lacked the diploma.

The dipolma classes were at the heart of the adult education program when it began in 1929. By 1969, the program still included a blend of general interest classes, basic education for the illiterate and preparation for diplomas.

When Young was appointed director that year, he and his staff conducted a survey. They discovered 23,000 adults in Arlington without high school diplomas. After discussions with the community and employers, they decided to build a career center, the contemporary name for the old "tech" school. About the same time, they began a program for Cuban refuggees, with an emphasis on data procesing and clerical skills and classes in English. While planning the career center, all these components started to mesh and a more diversified adult education program emerged.

Young now supervises a $7.5 million program, which is funded largely by federal grants and tuition. The lion's share of the almost completely self-supporting program is independent of the county school budget, with the exception of utility and maintenance costs at the facilities.

By far the largest component is the general interest series of up to 100 short-term classes which draw 14,000 students a year. Tuition is $1.35 per instructional hour. This summer the choices include stained glass, "gourmet living on a slim budget," stress management and filmmaking.

The most popular classes tend to be those that are job-related -- business courses and distributive education for training in hotel-motel management, banking, real estate sales and general merchandising. Most business students are employed and trying to get a better job, but about a fifth of them are homemakers entering or reentering the labor market.

In 1978-79, a total of 602 secondary students enrolled in the distributive education program. Adult students to totaled 4,705.

Industrial arts and trade, now studied by 29 percent of the secondary students, is drawing adults with both vocational and professional goals.

The trend among older adults toward second careers also has led them into retraining classes.

Not long ago, many of these students were between the ages of 32 and 40, returning for a high school diploma after their children were in school, after broken marriages or after moving unsuccessfully from job to job. It could take students as long as five years to earn their diploma.

Now many of the students are between 17 and 30 and, under a change implemented by Young, the classes have been accelerated. By attending classes six hours a day, five days a week, students can earn their diploma in three of four months.

"Basically, this is an alternative program to the regular public schools," said David Green, coordinator of one diploma program at Langston."We have people here for different reasons and not just because they are 'dropouts' . . . Maybe they had a problem in the home and had to leave school, or maybe they couldn't cope with size of the regular school classes. Numbers and cliques sometimes scare them."

Greg Matin, 20, left high school two years ago because the "atmosphere was too strict for my taste." Once out in the world, however, he discovered "you can't go anywhere without a high school diploma, and I didn't want to dig ditches all my life."

He is enthusiastic about studying for his dipolma at Langston because the "teachers are more like friends."

For the teachers, the work in adult education is also sometimes more attractive than regular classes.

Louise Nickens teachers six hours a day, five days a week, for 12 months without the long holiday vacations she would have had as a secondary teacher.

But as she sits among the clackety-clack of the typewriters, where her poverty-level students, some of them immigrants, come to learn how to do a job and earn a minimum wage at the same time, she is impressed by how serious they are.

"Teaching is my thing, wherever I am," said Nickens, a military wife. "It's rewarding in itself. But in high school, you feel if you lose one, or don't reach a success point with one, that they have another chance. Here it's sort of a last chance." CAPTION:

Picture 1, Ann Young and Gregory Rabe prepare soup.; Picture 2, Linda Moore and Virginia Reddy test a stew sauce.; Picture 3, Finishing touches in a drawing class.; Picture 4, Photography student Roger Hicks. Photos by Rick Reinhard for The Washington Post; Picture 5, Students in the high school diploma program at Langston School.; Picture 6, Shirley Marshall checks her figures against an adding machine.; Picture 7, Adult Education Director Bill Young. Photos by Vanessa Barnes Hillian -- The Washington Post; Picture 8, Juanita Golden help Kathy McCahill perfect sewing skills. By Rick Reinhard for The Washington Post