1) 220/128 + 350/256 = 220/128 + 175/128 = 395/128 = 3 11/128
2) 300/15 + 691/4 = 20 + 170 + 11/4 = 192 3/4
3) 111/40 + 561/6 = 2 31/40 + 93 3/6 = 95 31/40 + 20/40 = 95 51/40 = 96 11/40
4) 35/38 + 83/81 = (35*81+38*83)/(38*81) = 5989/3078 = 1 2911/3078