Design, simulate and verify a 16-bit ripple-carry adder by performing the following additions/subtractions (the values of a and b are given in decimal): (i) (-10) + (100), (ii) (63) - (-127), (iii) (15) + (95), (iv) (-32) + (79), (v) (-59) + (-16), (vi) (1000) + (2001), (vii) (-3210) + (15).