Should a tree trimmer be paid more than a registered nurse? Should a firefighter command a higher salary than a day-care worker?

How much do the differences in pay reflect the demands of the jobs, and to what extent do they reflect biases against jobs traditionally performed by women and minority-group men?

Armed with those questions, but with none of the answers, the Montgomery County Council yesterday received a bill to guarantee "equal pay for work of equal value" by including that concept as a principle in the county's merit system, the civil service code governing county employes.

Council Vice President Esther P. Gelman, the bill's sponsor, said it is aimed at correcting biases that put a higher value on so-called men's work. Gelman acknowledged that she has no specific evidence of where such biases exist, if at all, in the county government. A task force was formed last week to study the issue.

The bill would establish the "comparable worth" principle only for county employes, and would have no affect on the private sector. But, Gelman said, "In so many cases, we have put this county and this council on the cutting edge. We're trying to set a tone for other [private] employers."

The bill, if passed, would allow county employes who think they are not being paid fairly under the comparable worth principle to bring civil suits against the county, charging violation of the merit system.

Several other states have explored the question, often with controversial results. The state of Washington in 1974 found that women were paid only about 80 percent of what men were paid for jobs that were determined statistically to be equal in value. Bills to correct the inequities are pending before the state's legislature.

A similar study of Idaho state government workers produced a 1976 overhaul of the state's personnel system, with many employes having their salaries reduced and many clerical workers getting substantial pay raises. Comparable worth laws have been enacted in California and Wisconsin, and a bill is pending in Minnesota.

The council also unanimously approved a bill, sponsored by member Scott Fosler, to crack down on persons fencing stolen goods. The bill essentially expands the scope of last year's "precious metals" bills. The law is being broadened to include television sets, stereo equipment, china, antiques and other items. Those items must be held for 18 days before being resold.

The council also formally kicked off "Drunk and Drugged Driving Awareness Week," part of a national antidrunk driving campaign, by presenting an award to Paul Daley, cochairman of the Mothers Against Drunk Driving group.