a) 4/15 + 9/10 + 41/10 + 11/15 = (4/15 + 11/15) + (9/10 + 41/10) = 15/15 + 50/10 = 1 + 5 = 6
b) 17/16 + 12/13 + 15/16 + 14/13 = (17/16 + 15/16) + (12/13 + 14/13) = 32/16 + 26/13 = 2 + 2 = 4
c) 5/8 + 7/18 + 3/8 + 11/18 + 1/8 = (5/8 + 3/8 + 1/8) + (7/18 + 11/18) = 9/8 + 18/18 = 9/8 + 1 = 9/8 + 8/8 = 17/8
d) 8/14+ 5/14 + 1/3 + 1/14 + 2/3 = (8/14 + 5/14 + 1/14) + (1/3 + 2/3) = 14/14 + 3/3 = 1 + 1 = 2
