According to the debt reorganization plan, approved by the state consolidation committee, the governing body shall by resolution determine the rate or rates of interest to be paid on the bonds, not exceeding six percent (6%) per annum, and the time or times of payment of such interest, and the maturity or maturities of the bonds, which shall be at a time or times not exceeding twenty (20) years from the date of the bonds, in the case of funding bonds, and not exceeding thirty (30) years from the date of the bonds, in the case of refunding bonds; provided, that with the approval of the state consolidation committee, funding bonds may be made to mature at any time or times not exceeding thirty (30) years from the date of the bonds, and refunding bonds may be made to mature at any time or times not exceeding forty (40) years from the date of the bonds.