Jeff Popyack of 514 Valley Rd., Charlottesville, Va. 22903 has sent me a letter that says:

"maybe you're not the person I should be sending this letter to, but I'm hoping you will be able to get to the bottom of things.

"in reading The Post's excerpts from Ann Buchwald's 'Seems Like Yesterday,' I came across a passage that has me and my roommates throughly baffled."

The paragraph to which Jeff had reference was the one in which the newlywed Mrs. Buchwald was being instructed in the proper way to hang up a man's trousers. An English gentleman told her:

"You lay out the trousers flat on the bed, pat them smooth, fold back one pant leg to exactly half its length, place the hanger at that spot, fold the cuff end up to the crotch, turn the trousers over, and do the same with the other pant leg. A hurricane could't blow it off the hanger and miraculously the wrinkles come out faster."

To this, Jeff commented: "That paragraph seems innocuous enough, but if you're like me, you'll want to try hanging your pants that way. That's where the trouble begins.

"without going into any of the trouble we've had here, let me remark that none of my trousers are presently hanging in my closet, thanks to this article, and I face the distinct possibility of going to school tomorrow with a hanger wrapped around my leg.

"can you please clarify this mysterious technique?"

No, Jeff. I'm sorry to say that I can't. I am unable to visualize things of this kind and have little manual dexterity. When the telephone cord gets kinky and the receiver needs to be turned a few times to straighten it out, I can never figure out in which direction the receiver should be turned. I had so much trouble tying my shoelaces that I stopped buying shoes with laces. h

I was 32 years old before I learned to tie a bow tie. When I had to wear a tuxedo and became arm-weary from fussing with the black tie, Denny Sartain would sigh and say, "All right; lid down on the desk and I'll tie it for you," He used to work for an undertaker and that was the only way he could do it.

The instructions for hanging pants intrigued me as they did you, Jeff. A man never knows when a hurricane might hit his clothes closet, and I wanted to be prepared. So I laid out the instructions, and then I laid out a pair of trousers beside them. I did my level best to follow the instructions, but for some reason the pants, the hanger and I never did get our act together. In the end I was forced to conclude that either the instructions were given in code or I'm not very good at understanding instructions from wives -- my own or anybody else's.

The best I could do for you, Jeff, was to list your street address in the first paragraph so that if Mrs. Buchwald is of a mind to, she can drop you a line and explain matters. If you hear anything, pass it along. GAMBLING NEWS

If you're thinking of going up to an Atlantic City gambling casino to run a shoestring into a fortune, be advised that you are much more likely to run a fortune into a shoestring.

The Wall Street Journal has just reported on how Atlantic City's gambling joints fared in August. The figures indicate that your chances of breaking the bank are not good.

During August, the Boardwalk Regency casino had a gross win of $24,800,000. (In other words, its customers lost that much.) The gross win at Resorts International was a mere $24,300,000. Customers at Park Place lost $22,900,000 in August. And the city's newest and smallest casino the Brighton, didn't open until the middle of the month, so it won only $4,900,000. In all, those who gambled in Atlantic City during August lost more than $2,480,645, a day, or $103,360 an hour, 24 hours a day, seven days a week.

There is a reason to believe that this trend would remain intact even when tested by somebody who is as highly regarded in heaven as you are. THE POLITICAL OUTLOOK

The latest Washington Post poll reveals that President Carter and Gov. Reagan are now tied, with each favored by 37 percent of the voters.

Rep. Anderson and "Not Sure" are also tied, with 13 percent each, but Not Sure appears to be getting stronger with every passing day and could command a clear majority by November.

Vagrant though: When Cuban pollsters checked on Castro's popularity, do they include a sample of opinion from the Miami area? PUN FUN

Wendell Trogdon of the Indianapolis News says a new Tv series will be based on the Abscam scandals. It will be called "Here Comes the Bribe."