Fairfax County police said yesterday they have solved 300 burglaries committed between January, 1975, and last November with the arrest and conviction of three men, even though they were found guilty in only 10 of the burglary charges.

Police said the three men took such items as steroes, jewelry, cash, guns and television sets from homes and businesses in the Groveton area of the county, south of Alexandria. Police said they do not have an estimate of the worth of the items taken since none of the stolen property has been re-equered.

The burglaries are not related to the continuing silver gang burglary cases in which thieves have taken silver from suburban homes while leaving silver-plated items behind, police said.

The men arrested and convicted are:

Larry Dade, 23, of 2823 Mackell Ct, south of Alexandria, who pleaded guilty March 23 to six burglary charges and was sentenced to 20 years in prison.

Sammy Furgenson, 25, of 7803 Belford Dr., south of Alexandria, who was convicted March 2 of two burgaries and sentenced to none years in prison and on March 3 was found guilty of being an accessory after an armed robbery and sentenced to another none months in prison.

Jerry Sellers, 23, of the 8000 block of Fordson Road, south of Alexandria, who was convicted on March 4 of two counts of burglary and sentenced to five years' imprisonment.