When our racing maven Andrew Beyer wrote recently about the man who hit a $370,000 slot machine jackpot in Las Vegas, I'm sure many a reader thought, "Golly, maybe I could go out there and hit one, too." Before you buy your plane ticket, be advised that Jack Worden has done some research into your chances of hitting five 7s on a one-armed bandit. Jack says there are at least 25 stops on the Vegas slot machines (some new ones have more), so the odds on getting a 7 on any single reel are one in 25, and the odds on lining up five 7s are one in 9,765,625. Inasmuch as one must play a $3 a spin to qualify for the jackpot, Jack says that with average luck you should be able to win a $370,000 jackpot by feeding only $29,296,875 into the machine. I have checked Jack's figures and found them completely accurate.

On Jan. 7, Jean Fujinaga wrote me to complain that unsalted nuts are "never" on sale and always cost more than salted nuts. I saved Jean's letter on a hunch, just to see how long it would take for the situation to be corrected. Last week, salted and unsalted nuts were finally advertised here at the same sale price . . . The latest advertisement for gold coins at "bargain" prices is being run by a mail order house that doesn't even tell how much the coin weighs. Yet David P. Christovich of Alexandria tells me that some of these firms get 50,000 order a day . . . Former District Liner Frederick E. Morton Jr. now lives in Milan, Mich., and reports that people up there are saving empty cigarette packages in the mistaken notion that "the cigarette companies" will redeem them for cash contributions to buy medical equipment or provide free time on dialysis machines. They're still doing it here in Washington, too, Fred, although I've written 50 times that a phone call or letter to The Tobacco Institute Inc. will bring them a firm denial. The institute's phone number is 457-4800 and its mailing address is 1875 I St. NW . . . . My recent comments about the importance of advertising reminded colleague Dan Griffin of the line, "Doing business without advertising is like winking at a girl in the dark. You know what you're doing, but nobody else does." Dan thinks John Wanamaker said it, I think Mark Twain said it, and a 30-minute search of standard reference books turned up no support for either theory.

If pair refers to "two similiar or corresponding things," Richard Hamburger of Germantown wonders why golf tournament pairings refer to three or four players in a group. I can't answer the question, but the usage is sanctioned by modern dictionaries . . . . William Reynolds of Falls Church, whose wife has persuaded him not to carry credit cards, reports that one can't rent a car from the major rental firms unless he carries plastic money . . . . Del Bixler of Sarasota, F., writes: "Former humorist Earl Butz, now in the soup for income tax evasion, used to refer to Senators Bayh and Hartke as 'Mr. Bayh and Mr. Bought.' Now he can expand on that line with the addition of 'Mr. Caught.'" . . . Television actress Jean Stapleton says, "We adults have something in common with teenagers. They listen to rock groups and we listen to economists. None of us understands a word they're saying." . . . During Transportation Week, Herm Albright urged, "Take a Reaganite for a train ride -- while there's still time." . . . Danny Klayman tells me his car is so old the District issued him license plates with Roman numerials on them . . . Don Epperson says that every time he hears a luncheon speaker begin with, "I hardly know where to begin," he's tempted to call out, "Somewhere near the end." . . . Colleague John Means has formulated what he calls "Means' Law of Restaurant Illumination." His law states, "The harder the menu is to see, the higher the prices on it." Gold's Law says, "Menu prices rise in direct proportion to the number of French words used." . . . Bob Orben suggests that I reconsider my decision to retire. He warns, "Social Security is the ingenious plan that keeps you poor all your working years so that you can be poor during your retirement years." I'm not worried, Bob. The World's Greatest Grandson has purchased a power mower and gone into the lawn mowing business. He says he can use me part time, but cautions, "Until business improves, I can't afford to offer you a retirement plan, Grandpa."