DEAR BOB: We bought some land adjoining our house. At the closing, we were given a "quit claim deed." I didn't think anything of it, but my friends tell me I may not have gotten good title. Did I? Pat G., McLean.

DEAR PAT: Maybe. A quit claim deed conveys only whatever title the grantor owned. If he owned the full fee-simple title, that's what you got. If he didn't really own the land, you got nothing.

The best way to be sure you obtained good title is to obtain an owner's title insurance policy at the time of purchase. If the title insurer won't issue such a policy, title may be defective. Then see your attorney for aid in solving the title problem.

DEAD BOB: We hold a mortgage on a duplex we sold several years ago. I've contacted several banks about buying it from us, as we need the cash. Its balance is about $22,000. Buy the banks say they're not interested. How can we sell this mortgage? Manny S., Rockville.

DEAR MANNY: Banks and savings associations rarely buy mortgages from individuals, because the mortgages usually don't meet their lending rules.

Your resale market is through mortgage loan brokers, real estate brokers or the general public, via newspaper want ads.

Instead of selling, however, have you considered hypothecating the mortgage? That means you put it up as security for a loan from a bank or an individual. Many banks will loan up to about 50 percent or more of the mortgage balance. You'll still receive the monthly payments and will eventually receive the full $22,000. You may have to shop around, because not all banks hypothecate mortgages.

DEAR BOB: When we bought our home last year we didn't assume its FHA mortgage. But we make the monthly payments, of course. Can we deduct the interest even though the mortgage is still in the seller's name? Verona M., College Park.

DEAR VERONA: Yes. As long as you are the property's owner, you can deduct the mortgage interest. But you couldn't deduct the interest if you merely made payments on someone else's mortgage, such as making payments on your mother's home mortgage. Your tax advisor can give you more details.

DEAR BOB: Several years ago I sold my six-unit apartment house and took back a $24,000 second mortgae. The buyer hasn't paid me in four months and the building looks awful. What should I do? Hampton W., Washington.

DEAR HAMPTON: See your lawyer and start foreclosure. You may also be able to get a receiver appointed to manage the building. This can prevent the owner from "milking it" and taking out rent money while not properly maintaining the building. You may have waited too long.

DEAR BOB: We need a larger home, but aren't sure how much we can get for our present home. We'll have to use the equity in our current home as down payment on the larger home. Is it better to first buy the larger home or should we first sell our present home? Betty R., Rockville.

DEAR BETTY: Sell your present home first. Then you'll know exactly how much cash or mortgage notes you'll have for the down payment on the larger home. Try to allow a long closing period on your home sale so you'll have several months to shop for the larger home.

By selling your old home first, then you won't be under pressure to accept a low purchase offer for it to avoid making payments on two homes at once. If your home is priced at its fair market value, unless the local home sale market is temporarily depressed, it should sell in 30 to 60 days, 90 days at the most. When you list your home for sale with an agent, ask if a guaranteed trade-in plan is offered as this could ease your sale and purchase too.

DEAR BOB: What is the best time of the year to buy a home? Zola L., Washington.

DEAR ZOLA: Right now, before prices and mortgage interest rates go higher.

For a copy of the report, "How to Sell Your Home With or Without an Agent," send 25 cents in coin and a STAMPED, self-addressed envelope to Robert J. Bruss, P.O. Box 6710, San Francisco, Calif., 94101.