11.—(1) For the purpose of discharging any functions in pursuance of arrangements made under this Part—
(a)a council may appoint a committee of the council; or
(b)two or more councils may appoint a joint committee of those councils; or
(c)any such committee may appoint one or more sub-committees.
(2) Subject to this Act, the number of members of a committee appointed under subsection (1), their term of office, and the area (if restricted) within which the committee is to exercise its authority must be fixed by the appointing council or councils or, in the case of a sub-committee, by the appointing committee.
(3) A committee appointed under subsection (1), other than a committee for regulating and controlling the finance of the council, may, subject to section 15, include persons who are not members of the appointing council or councils or, in the case of a sub-committee, the council or councils of which it is a sub-committee.