18 5/12 + 8 10/17 + 23 7/12 + 28 7/17
First change them to improper fractions
18 5/12 = 221/12
8 10/17 = 146/17
23 7/12 = 283/12
28 7/17 = 483/17
now find the common denominator which would be 204
221/12 = 3757 /204
146/17 = 1752 /204
283/ 12 = 4811 /204
483/ 17 = 5796 /204
now add
(3757 + 1752 + 4811 + 5796) = 16,116/204
now divide
16,116 ÷ 204 = 79
Your answer is D. 79
Hope this helps. :)
