Within twenty years

Within twenty years: (a) an action upon a bond or other contract in writing secured by a mortgage of real property; (b) an action upon a sealed instrument, other than a sealed note and personal bond for the payment of money only whereon the period of limitation is the same as prescribed in Section 15-3-530, except that a sealed contract for sale or an offer to buy or sell goods whereon the period of limitation is the same as prescribed in Section 36-2-725.